diff --git a/src/main/java/racal/sunyard/main/SydApi4j.java b/src/main/java/racal/sunyard/main/SydApi4j.java
index db5337e..e76a3be 100644
--- a/src/main/java/racal/sunyard/main/SydApi4j.java
+++ b/src/main/java/racal/sunyard/main/SydApi4j.java
@@ -2113,7 +2113,7 @@ public class SydApi4j implements SydApi {
         HashMap<String, Object> data = new HashMap<String, Object>();
         data.put("alg$option", nAlg - 0x30);
         data.put("certificateModel$option", 0);
-        data.put("certificateSn", certSerial);
+        data.put("certificateSn", certSerial.getBytes());
         data.put("keyType", "X");
         packet.put("data", data);
         // 渲染发送 耗时长
diff --git a/src/test/java/com/sunyard/sydapi/test/TestAllMethods.java b/src/test/java/com/sunyard/sydapi/test/TestAllMethods.java
index a3e28f6..fbe78cf 100644
--- a/src/test/java/com/sunyard/sydapi/test/TestAllMethods.java
+++ b/src/test/java/com/sunyard/sydapi/test/TestAllMethods.java
@@ -4,7 +4,6 @@ import com.sunyard.RetWrap;
 import com.sunyard.SydApi;
 import com.sunyard.cert.X509;
 import com.sunyard.proto.Util;
-import com.sunyard.sydapi.util.PrintUtil;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
@@ -16,6 +15,9 @@ import java.io.*;
 import static com.sunyard.sydapi.util.PrintUtil.printByteArray;
 import static com.sunyard.sydapi.util.PrintUtil.printRetWrap;
 
+/**
+ * 所有方法的测试类
+ */
 public class TestAllMethods {
 
     SydApi4j api;