diff --git a/ios/Classes/Api/MOP_smsign.h b/ios/Classes/Api/MOP_smsign.h
new file mode 100644
index 0000000..3ab4579
--- /dev/null
+++ b/ios/Classes/Api/MOP_smsign.h
@@ -0,0 +1,19 @@
+//
+//  MOP_smsign.h
+//  mop
+//
+//  Created by beetle_92 on 2021/4/21.
+//
+
+#import <Foundation/Foundation.h>
+#import "MOPBaseApi.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface MOP_smsign : MOPBaseApi
+
+@property (nonatomic, copy) NSString *plainText;
+
+@end
+
+NS_ASSUME_NONNULL_END
diff --git a/ios/Classes/Api/MOP_smsign.m b/ios/Classes/Api/MOP_smsign.m
new file mode 100644
index 0000000..9058ee4
--- /dev/null
+++ b/ios/Classes/Api/MOP_smsign.m
@@ -0,0 +1,21 @@
+//
+//  MOP_smsign.m
+//  mop
+//
+//  Created by beetle_92 on 2021/4/21.
+//
+
+#import "MOP_smsign.h"
+#import <FinApplet/FinApplet.h>
+
+@implementation MOP_smsign
+
+- (void)setupApiWithSuccess:(void (^)(NSDictionary<NSString *,id> * _Nonnull))success failure:(void (^)(id _Nullable))failure cancel:(void (^)(void))cancel
+{
+    NSLog(@"smsign");
+    NSString *signature = [[FATClient sharedClient] getSM3String:self.plainText];
+    NSLog(@"signature = %@", signature);
+    success(@{@"data": signature});
+}
+
+@end
diff --git a/ios/mop.podspec b/ios/mop.podspec
index 4cd4676..711d709 100644
--- a/ios/mop.podspec
+++ b/ios/mop.podspec
@@ -17,7 +17,7 @@ A finclip miniprogram flutter sdk.
   s.dependency 'Flutter'
   s.ios.deployment_target = '9.0'
 
-  s.dependency 'FinApplet' , '2.24.3'
-  s.dependency 'FinAppletExt' , '2.24.3'
+  s.dependency 'FinApplet' , '2.25.0-alpha20210421v01'
+  s.dependency 'FinAppletExt' , '2.25.0-alpha20210421v01'
 end
 
diff --git a/lib/mop.dart b/lib/mop.dart
index 1ab0a4b..d8f6d69 100644
--- a/lib/mop.dart
+++ b/lib/mop.dart
@@ -195,4 +195,13 @@ class Mop {
     _extensionApis[name] = handler;
     _channel.invokeMethod("registerExtensionApi", {"name": name});
   }
+
+  /// 获取国密加密
+  Future<String> getSMSign(String plainText) async {
+    var result =
+        await _channel.invokeMapMethod("smsign", {'plainText': plainText});
+    var data = result['data']['data'];
+    print(data);
+    return data;
+  }
 }