diff --git a/Example/Example.xcodeproj/project.pbxproj b/Example/Example.xcodeproj/project.pbxproj
index 93de2f6a..2a34f555 100644
--- a/Example/Example.xcodeproj/project.pbxproj
+++ b/Example/Example.xcodeproj/project.pbxproj
@@ -513,7 +513,7 @@
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
-				IPHONEOS_DEPLOYMENT_TARGET = 8.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 9.0;
 				MTL_ENABLE_DEBUG_INFO = INCLUDE_SOURCE;
 				MTL_FAST_MATH = YES;
 				ONLY_ACTIVE_ARCH = YES;
@@ -566,7 +566,7 @@
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
-				IPHONEOS_DEPLOYMENT_TARGET = 8.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 9.0;
 				MTL_ENABLE_DEBUG_INFO = NO;
 				MTL_FAST_MATH = YES;
 				SDKROOT = iphoneos;
@@ -583,7 +583,7 @@
 				CODE_SIGN_STYLE = Automatic;
 				DEVELOPMENT_TEAM = 75FYWDWHL5;
 				INFOPLIST_FILE = "$(SRCROOT)/SensorsData/Info.plist";
-				IPHONEOS_DEPLOYMENT_TARGET = 8.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 9.0;
 				LD_RUNPATH_SEARCH_PATHS = (
 					"$(inherited)",
 					"@executable_path/Frameworks",
@@ -603,7 +603,7 @@
 				CODE_SIGN_STYLE = Automatic;
 				DEVELOPMENT_TEAM = 75FYWDWHL5;
 				INFOPLIST_FILE = "$(SRCROOT)/SensorsData/Info.plist";
-				IPHONEOS_DEPLOYMENT_TARGET = 8.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 9.0;
 				LD_RUNPATH_SEARCH_PATHS = (
 					"$(inherited)",
 					"@executable_path/Frameworks",
@@ -622,7 +622,7 @@
 				CODE_SIGN_STYLE = Automatic;
 				DEVELOPMENT_TEAM = 75FYWDWHL5;
 				INFOPLIST_FILE = SensorsDataSwift/Info.plist;
-				IPHONEOS_DEPLOYMENT_TARGET = 8.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 9.0;
 				LD_RUNPATH_SEARCH_PATHS = (
 					"$(inherited)",
 					"@executable_path/Frameworks",
@@ -644,7 +644,7 @@
 				CODE_SIGN_STYLE = Automatic;
 				DEVELOPMENT_TEAM = 75FYWDWHL5;
 				INFOPLIST_FILE = SensorsDataSwift/Info.plist;
-				IPHONEOS_DEPLOYMENT_TARGET = 8.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 9.0;
 				LD_RUNPATH_SEARCH_PATHS = (
 					"$(inherited)",
 					"@executable_path/Frameworks",
diff --git a/SensorsAnalyticsSDK.podspec b/SensorsAnalyticsSDK.podspec
index 6e2f0c35..c0dd47e7 100644
--- a/SensorsAnalyticsSDK.podspec
+++ b/SensorsAnalyticsSDK.podspec
@@ -1,12 +1,12 @@
 Pod::Spec.new do |s|
   s.name         = "SensorsAnalyticsSDK"
-  s.version      = "4.5.6"
+  s.version      = "4.5.7"
   s.summary      = "The official iOS SDK of Sensors Analytics."
   s.homepage     = "http://www.sensorsdata.cn"
   s.source       = { :git => 'https://github.com/sensorsdata/sa-sdk-ios.git', :tag => "v#{s.version}" }
   s.license = { :type => "Apache License, Version 2.0" }
   s.author = { "Yuhan ZOU" => "zouyuhan@sensorsdata.cn" }
-  s.ios.deployment_target = '8.0'
+  s.ios.deployment_target = '9.0'
   s.osx.deployment_target = '10.10'
   s.default_subspec = 'Core'
   s.frameworks = 'Foundation', 'SystemConfiguration'
@@ -47,7 +47,7 @@ Pod::Spec.new do |s|
 
   # 全埋点
   s.subspec 'AutoTrack' do |g|
-    g.ios.deployment_target = '8.0'
+    g.ios.deployment_target = '9.0'
     g.dependency 'SensorsAnalyticsSDK/Common'
     g.source_files = "SensorsAnalyticsSDK/AutoTrack/**/*.{h,m}"
     g.public_header_files = 'SensorsAnalyticsSDK/AutoTrack/SensorsAnalyticsSDK+SAAutoTrack.h', 'SensorsAnalyticsSDK/AutoTrack/SAConfigOptions+AutoTrack.h'
@@ -56,7 +56,7 @@ Pod::Spec.new do |s|
 
 # 可视化相关功能，包含可视化全埋点和点击图
   s.subspec 'Visualized' do |f|
-    f.ios.deployment_target = '8.0'
+    f.ios.deployment_target = '9.0'
     f.dependency 'SensorsAnalyticsSDK/AutoTrack'
     f.source_files = "SensorsAnalyticsSDK/Visualized/**/*.{h,m}"
     f.public_header_files = 'SensorsAnalyticsSDK/Visualized/SensorsAnalyticsSDK+Visualized.h', 'SensorsAnalyticsSDK/Visualized/SAConfigOptions+Visualized.h'
@@ -64,7 +64,7 @@ Pod::Spec.new do |s|
 
   # 开启 GPS 定位采集
   s.subspec 'Location' do |f|
-    f.ios.deployment_target = '8.0'
+    f.ios.deployment_target = '9.0'
     f.frameworks = 'CoreLocation'
     f.dependency 'SensorsAnalyticsSDK/Core'
     f.source_files = "SensorsAnalyticsSDK/Location/**/*.{h,m}"
@@ -73,7 +73,7 @@ Pod::Spec.new do |s|
 
   # 开启设备方向采集
   s.subspec 'DeviceOrientation' do |f|
-    f.ios.deployment_target = '8.0'
+    f.ios.deployment_target = '9.0'
     f.dependency 'SensorsAnalyticsSDK/Core'
     f.source_files = 'SensorsAnalyticsSDK/DeviceOrientation/**/*.{h,m}'
     f.public_header_files = 'SensorsAnalyticsSDK/DeviceOrientation/SensorsAnalyticsSDK+DeviceOrientation.h'
@@ -82,7 +82,7 @@ Pod::Spec.new do |s|
 
   # 推送点击
   s.subspec 'AppPush' do |f|
-    f.ios.deployment_target = '8.0'
+    f.ios.deployment_target = '9.0'
     f.dependency 'SensorsAnalyticsSDK/Core'
     f.source_files = "SensorsAnalyticsSDK/AppPush/**/*.{h,m}"
     f.public_header_files = 'SensorsAnalyticsSDK/AppPush/SAConfigOptions+AppPush.h'
@@ -90,7 +90,7 @@ Pod::Spec.new do |s|
 
   # 使用崩溃事件采集
   s.subspec 'Exception' do |e|
-    e.ios.deployment_target = '8.0'
+    e.ios.deployment_target = '9.0'
     e.dependency 'SensorsAnalyticsSDK/Common'
     e.source_files  =  "SensorsAnalyticsSDK/Exception/**/*.{h,m}"
     e.public_header_files = 'SensorsAnalyticsSDK/Exception/SAConfigOptions+Exception.h'
@@ -98,7 +98,7 @@ Pod::Spec.new do |s|
 
   # 基于 UA，使用 UIWebView 或者 WKWebView 进行打通
   s.subspec 'WebView' do |w|
-    w.ios.deployment_target = '8.0'
+    w.ios.deployment_target = '9.0'
     w.dependency 'SensorsAnalyticsSDK/Core'
     w.source_files  =  "SensorsAnalyticsSDK/WebView/**/*.{h,m}"
     w.public_header_files = 'SensorsAnalyticsSDK/WebView/SensorsAnalyticsSDK+WebView.h'
@@ -106,7 +106,7 @@ Pod::Spec.new do |s|
 
   # 基于 UA，使用 WKWebView 进行打通
   s.subspec 'WKWebView' do |w|
-    w.ios.deployment_target = '8.0'
+    w.ios.deployment_target = '9.0'
     w.dependency 'SensorsAnalyticsSDK/Core'
     w.source_files  =  "SensorsAnalyticsSDK/WKWebView/**/*.{h,m}"
     w.public_header_files = 'SensorsAnalyticsSDK/WKWebView/SensorsAnalyticsSDK+WKWebView.h'
@@ -119,14 +119,14 @@ Pod::Spec.new do |s|
   end
 
   s.subspec 'DeprecatedCellClick' do |d|
-    d.ios.deployment_target = '8.0'
+    d.ios.deployment_target = '9.0'
     d.dependency 'SensorsAnalyticsSDK/Core'
     d.source_files = 'CellClick_HookDelegate_Deprecated/*.{h,m}'
     d.project_header_files = 'CellClick_HookDelegate_Deprecated/*.h'
   end
 
   s.subspec 'Exposure' do |h|
-    h.ios.deployment_target = '8.0'
+    h.ios.deployment_target = '9.0'
     h.dependency 'SensorsAnalyticsSDK/Common'
     h.source_files = 'SensorsAnalyticsSDK/Exposure/**/*.{h,m}'
     h.public_header_files = 'SensorsAnalyticsSDK/Exposure/SAConfigOptions+Exposure.h', 'SensorsAnalyticsSDK/Exposure/SAExposureConfig.h', 'SensorsAnalyticsSDK/Exposure/SAExposureData.h', 'SensorsAnalyticsSDK/Exposure/SensorsAnalyticsSDK+Exposure.h', 'SensorsAnalyticsSDK/Exposure/UIView+ExposureIdentifier.h'
diff --git a/SensorsAnalyticsSDK.xcodeproj/project.pbxproj b/SensorsAnalyticsSDK.xcodeproj/project.pbxproj
index e6035922..166badd7 100644
--- a/SensorsAnalyticsSDK.xcodeproj/project.pbxproj
+++ b/SensorsAnalyticsSDK.xcodeproj/project.pbxproj
@@ -3044,7 +3044,7 @@
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
-				IPHONEOS_DEPLOYMENT_TARGET = 8.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 9.0;
 				MTL_ENABLE_DEBUG_INFO = INCLUDE_SOURCE;
 				MTL_FAST_MATH = YES;
 				ONLY_ACTIVE_ARCH = YES;
@@ -3100,7 +3100,7 @@
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
-				IPHONEOS_DEPLOYMENT_TARGET = 8.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 9.0;
 				MTL_ENABLE_DEBUG_INFO = NO;
 				MTL_FAST_MATH = YES;
 				SDKROOT = iphoneos;
@@ -3126,7 +3126,7 @@
 				GENERATE_MASTER_OBJECT_FILE = YES;
 				INFOPLIST_FILE = "$(SRCROOT)/SupportingFiles/SensorsAnalyticsSDK-Info.plist";
 				INSTALL_PATH = "$(LOCAL_LIBRARY_DIR)/Frameworks";
-				IPHONEOS_DEPLOYMENT_TARGET = 8.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 9.0;
 				LD_RUNPATH_SEARCH_PATHS = (
 					"$(inherited)",
 					"@executable_path/Frameworks",
@@ -3161,7 +3161,7 @@
 				GENERATE_MASTER_OBJECT_FILE = YES;
 				INFOPLIST_FILE = "$(SRCROOT)/SupportingFiles/SensorsAnalyticsSDK-Info.plist";
 				INSTALL_PATH = "$(LOCAL_LIBRARY_DIR)/Frameworks";
-				IPHONEOS_DEPLOYMENT_TARGET = 8.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 9.0;
 				LD_RUNPATH_SEARCH_PATHS = (
 					"$(inherited)",
 					"@executable_path/Frameworks",
@@ -3187,7 +3187,7 @@
 				DEVELOPMENT_TEAM = 75FYWDWHL5;
 				GCC_PREPROCESSOR_DEFINITIONS = "$(inherited)";
 				INFOPLIST_FILE = SensorsAnalyticsTests/Info.plist;
-				IPHONEOS_DEPLOYMENT_TARGET = 8.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 9.0;
 				LD_RUNPATH_SEARCH_PATHS = (
 					"$(inherited)",
 					"@executable_path/Frameworks",
@@ -3205,7 +3205,7 @@
 				CODE_SIGN_STYLE = Automatic;
 				DEVELOPMENT_TEAM = 75FYWDWHL5;
 				INFOPLIST_FILE = SensorsAnalyticsTests/Info.plist;
-				IPHONEOS_DEPLOYMENT_TARGET = 8.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 9.0;
 				LD_RUNPATH_SEARCH_PATHS = (
 					"$(inherited)",
 					"@executable_path/Frameworks",
diff --git a/SensorsAnalyticsSDK/Core/Builder/EventObject/SAPropertyValidator.m b/SensorsAnalyticsSDK/Core/Builder/EventObject/SAPropertyValidator.m
index 58e74233..27edd5fa 100644
--- a/SensorsAnalyticsSDK/Core/Builder/EventObject/SAPropertyValidator.m
+++ b/SensorsAnalyticsSDK/Core/Builder/EventObject/SAPropertyValidator.m
@@ -36,9 +36,15 @@ - (void)sensorsdata_isValidPropertyKeyWithError:(NSError *__autoreleasing  _Null
 }
 
 - (id)sensorsdata_propertyValueWithKey:(NSString *)key error:(NSError *__autoreleasing  _Nullable *)error {
-    NSUInteger length = [self lengthOfBytesUsingEncoding:NSUTF8StringEncoding];
-    if (length > kSAPropertyValueMaxLength) {
-        SALogWarn(@"%@'s length is longer than %ld", self, kSAPropertyValueMaxLength);
+    NSInteger maxLength = kSAPropertyValueMaxLength;
+    if ([key isEqualToString:@"app_crashed_reason"]) {
+        maxLength = maxLength * 2;
+    }
+    if (self.length >= maxLength) {
+        SALogWarn(@"%@'s length is longer than %ld", self, maxLength);
+        NSMutableString *tempString = [NSMutableString stringWithString:[self substringToIndex:maxLength - 1]];
+        [tempString appendString:@"$"];
+        return [tempString copy];
     }
     return self;
 }
diff --git a/SensorsAnalyticsSDK/Core/Interceptor/Flush/SARepeatFlushInterceptor.m b/SensorsAnalyticsSDK/Core/Interceptor/Flush/SARepeatFlushInterceptor.m
index c7c4e06b..e611bce6 100644
--- a/SensorsAnalyticsSDK/Core/Interceptor/Flush/SARepeatFlushInterceptor.m
+++ b/SensorsAnalyticsSDK/Core/Interceptor/Flush/SARepeatFlushInterceptor.m
@@ -25,7 +25,7 @@
 #import "SARepeatFlushInterceptor.h"
 #import "SAFlowManager.h"
 
-static NSInteger const kSAFlushMaxRepeatCount = 100;
+static NSInteger const kSAFlushMaxRepeatCount = 40;
 
 @interface SARepeatFlushInterceptor ()
 @end
diff --git a/SensorsAnalyticsSDK/Core/Network/SACarrierNamePropertyPlugin.m b/SensorsAnalyticsSDK/Core/Network/SACarrierNamePropertyPlugin.m
index c303cece..f268d9a6 100644
--- a/SensorsAnalyticsSDK/Core/Network/SACarrierNamePropertyPlugin.m
+++ b/SensorsAnalyticsSDK/Core/Network/SACarrierNamePropertyPlugin.m
@@ -28,6 +28,7 @@
 #import "SAConstants+Private.h"
 #import "SALimitKeyManager.h"
 #import "SAValidator.h"
+#import "SACoreResources.h"
 
 #if TARGET_OS_IOS && !TARGET_OS_MACCATALYST
 #import <CoreTelephony/CTTelephonyNetworkInfo.h>
@@ -40,6 +41,7 @@
 @interface SACarrierNamePropertyPlugin()
 #if TARGET_OS_IOS && !TARGET_OS_MACCATALYST
 @property (nonatomic, strong) CTTelephonyNetworkInfo *networkInfo;
+@property (nonatomic, strong) CTCarrier *carrier;
 #endif
 @end
 @implementation SACarrierNamePropertyPlugin
@@ -71,24 +73,16 @@ - (NSString *)currentCarrierName {
     NSString *carrierName = nil;
 
     @try {
-        CTCarrier *carrier = nil;
-
-#ifdef __IPHONE_12_0
-        if (@available(iOS 12.1, *)) {
-            // 排序
-            NSArray *carrierKeysArray = [self.networkInfo.serviceSubscriberCellularProviders.allKeys sortedArrayUsingSelector:@selector(compare:)];
-            carrier = self.networkInfo.serviceSubscriberCellularProviders[carrierKeysArray.firstObject];
-            if (!carrier.mobileNetworkCode) {
-                carrier = self.networkInfo.serviceSubscriberCellularProviders[carrierKeysArray.lastObject];
+        if (self.carrier != nil) {
+            NSString *networkCode = nil;
+            if ([self.carrier respondsToSelector:@selector(mobileNetworkCode)]) {
+                networkCode = [self.carrier mobileNetworkCode];
+            }
+            
+            NSString *countryCode = nil;
+            if ([self.carrier respondsToSelector:@selector(mobileCountryCode)]) {
+                countryCode = [self.carrier mobileCountryCode];
             }
-        }
-#endif
-        if (!carrier) {
-            carrier = self.networkInfo.subscriberCellularProvider;
-        }
-        if (carrier != nil) {
-            NSString *networkCode = [carrier mobileNetworkCode];
-            NSString *countryCode = [carrier mobileCountryCode];
 
             // 中国运营商 mcc 标识
             NSString *carrierChinaMCC = @"460";
@@ -116,12 +110,7 @@ - (NSString *)currentCarrierName {
                     carrierName = SALocalizedString(@"SAPresetPropertyCarrierTietong");
                 }
             } else if (countryCode && networkCode) { //国外运营商解析
-                //加载当前 bundle
-                NSBundle *sensorsBundle = [NSBundle bundleWithPath:[[NSBundle bundleForClass:[self class]] pathForResource:@"SensorsAnalyticsSDK" ofType:@"bundle"]];
-                //文件路径
-                NSString *jsonPath = [sensorsBundle pathForResource:@"sa_mcc_mnc_mini.json" ofType:nil];
-                NSData *jsonData = [NSData dataWithContentsOfFile:jsonPath];
-                NSDictionary *dicAllMcc = [SAJSONUtil JSONObjectWithData:jsonData];
+                NSDictionary *dicAllMcc = [SACoreResources mcc];
                 if (dicAllMcc) {
                     NSString *mccMncKey = [NSString stringWithFormat:@"%@%@", countryCode, networkCode];
                     carrierName = dicAllMcc[mccMncKey];
@@ -133,6 +122,26 @@ - (NSString *)currentCarrierName {
     }
     return carrierName;
 }
+
+- (CTCarrier *)carrier {
+    if (!_carrier) {
+#ifdef __IPHONE_12_0
+        if (@available(iOS 12.1, *)) {
+            // 排序
+            NSArray *carrierKeysArray = [self.networkInfo.serviceSubscriberCellularProviders.allKeys sortedArrayUsingSelector:@selector(compare:)];
+            _carrier = self.networkInfo.serviceSubscriberCellularProviders[carrierKeysArray.firstObject];
+            if (![_carrier respondsToSelector:@selector(mobileNetworkCode)] || !_carrier.mobileNetworkCode) {
+                _carrier = self.networkInfo.serviceSubscriberCellularProviders[carrierKeysArray.lastObject];
+            }
+        }
+#endif
+        if (!_carrier && [self.networkInfo respondsToSelector:@selector(subscriberCellularProvider)]) {
+            _carrier = self.networkInfo.subscriberCellularProvider;
+        }
+    }
+    return _carrier;
+}
+
 #endif
 
 #pragma mark - SAPropertyPlugin method
diff --git a/SensorsAnalyticsSDK/Core/SAConstants.m b/SensorsAnalyticsSDK/Core/SAConstants.m
index 2fd20d01..32841719 100644
--- a/SensorsAnalyticsSDK/Core/SAConstants.m
+++ b/SensorsAnalyticsSDK/Core/SAConstants.m
@@ -188,7 +188,7 @@ void sensorsdata_dispatch_safe_sync(dispatch_queue_t queue,DISPATCH_NOESCAPE dis
 
 //event name、property key、value max length
 NSInteger kSAEventNameMaxLength = 100;
-NSInteger kSAPropertyValueMaxLength = 1024;
+NSInteger kSAPropertyValueMaxLength = 8192;
 
 #pragma mark - SA Visualized
 /// 埋点校验中，$WebClick 匹配可视化全埋点的事件名（集合）
diff --git a/SensorsAnalyticsSDK/Core/SensorsAnalyticsSDK.m b/SensorsAnalyticsSDK/Core/SensorsAnalyticsSDK.m
index b1a2157f..3446ac8e 100755
--- a/SensorsAnalyticsSDK/Core/SensorsAnalyticsSDK.m
+++ b/SensorsAnalyticsSDK/Core/SensorsAnalyticsSDK.m
@@ -64,7 +64,7 @@
 #import "SALimitKeyManager.h"
 #import "NSDictionary+SACopyProperties.h"
 
-#define VERSION @"4.5.6"
+#define VERSION @"4.5.7"
 
 void *SensorsAnalyticsQueueTag = &SensorsAnalyticsQueueTag;