diff --git a/src/main/java/component/SignatureField.java b/src/main/java/component/SignatureField.java
index 87ee0fd..103d8b6 100644
--- a/src/main/java/component/SignatureField.java
+++ b/src/main/java/component/SignatureField.java
@@ -13,10 +13,9 @@ import java.util.List;
  * @Copyright: MIN-Group；国家重大科技基础设施——未来网络北大实验室；深圳市信息论与未来网络重点实验室
  */
 class SignatureContainer {
-    private List<Signature> signatures;
+    private List<Signature> signatures= new LinkedList<>();;
 
     public SignatureContainer() {
-        signatures = new LinkedList<>();
     }
 
     /**
@@ -74,10 +73,9 @@ class SignatureContainer {
 }
 
 public class SignatureField implements TlvComponentBase, IEncodingAble {
-    private SignatureContainer signatures;
+    private SignatureContainer signatures= new SignatureContainer();
 
     public SignatureField() {
-        signatures = new SignatureContainer();
     }
 
     public SignatureField(SignatureContainer container) {
@@ -120,6 +118,7 @@ public class SignatureField implements TlvComponentBase, IEncodingAble {
      */
     @Override
     public int wireEncode(Encoder encoder) throws ComponentException {
+        try{
         // 如果签名区没有签名，则可以直接去掉签名区 TLV，因为它不是必须的
         if (signatures.length() == 0) {
             return -1;
@@ -129,8 +128,7 @@ public class SignatureField implements TlvComponentBase, IEncodingAble {
         // 反向遍历，可以保证解码的时候正向输出
         for (int i = signatures.length() - 1; i >= 0; i--) {
             Signature newSignature = signatures.getElement(i);
-            int tmplen = 0;
-            tmplen = newSignature.getSigValue().wireEncode(encoder);
+            int tmplen = newSignature.getSigValue().wireEncode(encoder);
             if (tmplen <= 0) {
                 return -1;
             }
@@ -143,29 +141,23 @@ public class SignatureField implements TlvComponentBase, IEncodingAble {
         }
 
         // 编码签名区 TLV-LENGTH
-        int tmplen = 0;
-        try {
-            tmplen = encoder.prependVarNumber(new VlInt(totalLength));
-        } catch (EncoderException e) {
-            throw new ComponentException("SignatureField.wireEncode: " + e.getMessage());
-        }
+        int tmplen = encoder.prependVarNumber(new VlInt(totalLength));
         if (tmplen <= 0) {
             return -1;
         }
         totalLength += tmplen;
 
         // 编码签名区 TLV-TYPE
-        try {
-            tmplen = encoder.prependVarNumber(new VlInt(TLV.TlvSignatureField));
-        } catch (EncoderException e) {
-            throw new ComponentException("SignatureField.wireEncode: " + e.getMessage());
-        }
+        tmplen = encoder.prependVarNumber(new VlInt(TLV.TlvSignatureField));
         if (tmplen <= 0) {
             return -1;
         }
         totalLength += tmplen;
 
         return totalLength;
+    } catch (EncoderException e) {
+        throw new ComponentException("SignatureField.wireEncode: " + e.getMessage());
+    }
     }
 
     /**
@@ -186,11 +178,9 @@ public class SignatureField implements TlvComponentBase, IEncodingAble {
             if (!block.parseSubElements()) {
                 return false;
             }
-
             ElementContainer subElements = block.getSubElements();
             int subElementNum = subElements.length();
             if (subElementNum % 2 != 0) {
-//            throw new Error("SignatureField.wireDecode: Invalid SignatureField TLV, require even num sub element");
                 return false;
             }
 
diff --git a/src/test/java/component/SignatureFieldTest.java b/src/test/java/component/SignatureFieldTest.java
new file mode 100644
index 0000000..e328722
--- /dev/null
+++ b/src/test/java/component/SignatureFieldTest.java
@@ -0,0 +1,140 @@
+package component;
+
+import encoding.*;
+import org.junit.Test;
+
+import java.util.Arrays;
+
+/*
+ * @Author: Wang Feng
+ * @Description:
+ * @Version: 1.0.0
+ * @Date: 21:00 2021/4/1
+ * @Copyright: MIN-Group；国家重大科技基础设施——未来网络北大实验室；深圳市信息论与未来网络重点实验室
+ */
+public class SignatureFieldTest {
+    @Test
+    public void TestSignatureField_AddSignature() throws ComponentException {
+        byte[] buf={(byte)1, (byte)2, (byte)3, (byte)4,
+                (byte)5, (byte)6, (byte)7, (byte)8};
+        SignatureValue got=new SignatureValue(buf);
+        byte[] buf1={(byte)1, (byte)2, (byte)3, (byte)4,
+                (byte)5, (byte)6, (byte)7, (byte)9};
+        SignatureValue got1=new SignatureValue(buf1);
+
+        SignatureAlgorithm value=new SignatureAlgorithm(0);
+        SignatureInfo info=new SignatureInfo(value);
+
+        Signature signature=new Signature(info,got);
+        Signature signature1=new Signature(info,got1);
+
+        SignatureContainer container=new SignatureContainer();
+        container.addElement(signature);
+
+        SignatureField field=new SignatureField(container);
+        System.out.println("signature num: "+field.getSignatures().length());
+        field.addSignature(signature1);
+        System.out.println("signature num: "+field.getSignatures().length());
+    }
+
+    @Test
+    public void TestSignatureField_GetSignature() throws ComponentException {
+        byte[] buf={(byte)1, (byte)2, (byte)3, (byte)4,
+                (byte)5, (byte)6, (byte)7, (byte)8};
+        SignatureValue got=new SignatureValue(buf);
+        byte[] buf1={(byte)1, (byte)2, (byte)3, (byte)4,
+                (byte)5, (byte)6, (byte)7, (byte)9};
+        SignatureValue got1=new SignatureValue(buf1);
+
+        SignatureAlgorithm value=new SignatureAlgorithm(0);
+        SignatureInfo info=new SignatureInfo(value);
+
+        Signature signature=new Signature(info,got);
+        Signature signature1=new Signature(info,got1);
+
+        SignatureContainer container=new SignatureContainer();
+        container.addElement(signature);
+
+        SignatureField field=new SignatureField(container);
+        field.addSignature(signature1);
+        System.out.println("signature num: "+field.getSignatures().length());
+        Signature get=field.getSignature(0);
+        System.out.println("type: "+get.getSigInfo().getSignatureType().getValue().getSignatureAlgorithm());
+        System.out.println("keylocator: "+get.getSigInfo().getKeyLocator().getIdentifier().toUri());
+        System.out.println("value: "+ Arrays.toString(get.getSigValue().getValue()));
+    }
+
+    @Test
+    public void TestSignatureField_GetSignatures() throws ComponentException {
+        byte[] buf={(byte)1, (byte)2, (byte)3, (byte)4,
+                (byte)5, (byte)6, (byte)7, (byte)8};
+        SignatureValue got=new SignatureValue(buf);
+        byte[] buf1={(byte)1, (byte)2, (byte)3, (byte)4,
+                (byte)5, (byte)6, (byte)7, (byte)9};
+        SignatureValue got1=new SignatureValue(buf1);
+
+        SignatureAlgorithm value=new SignatureAlgorithm(0);
+        SignatureInfo info=new SignatureInfo(value);
+
+        Signature signature=new Signature(info,got);
+        Signature signature1=new Signature(info,got1);
+
+        SignatureContainer container=new SignatureContainer();
+        container.addElement(signature);
+
+        SignatureField field=new SignatureField(container);
+        field.addSignature(signature1);
+        System.out.println("signature num: "+field.getSignatures().length());
+        Signature get=field.getSignatures().getElement(1);
+        System.out.println("type: "+get.getSigInfo().getSignatureType().getValue().getSignatureAlgorithm());
+        System.out.println("keylocator: "+get.getSigInfo().getKeyLocator().getIdentifier().toUri());
+        System.out.println("value: "+ Arrays.toString(get.getSigValue().getValue()));
+    }
+
+    @Test
+    public void TestSignatureField_WireDecode() throws EncoderException, ComponentException, BlockException {
+        byte[] buf={(byte)1, (byte)2, (byte)3, (byte)4,
+                (byte)5, (byte)6, (byte)7, (byte)8};
+        SignatureValue got=new SignatureValue(buf);
+        byte[] buf1={(byte)1, (byte)2, (byte)3, (byte)4,
+                (byte)5, (byte)6, (byte)7, (byte)9};
+        SignatureValue got1=new SignatureValue(buf1);
+
+        SignatureAlgorithm value=new SignatureAlgorithm(0);
+        SignatureInfo info=new SignatureInfo(value);
+
+        Signature signature=new Signature(info,got);
+        Signature signature1=new Signature(info,got1);
+
+        SignatureContainer container=new SignatureContainer();
+        container.addElement(signature);
+
+        SignatureField field=new SignatureField(container);
+        field.addSignature(signature1);
+        System.out.println("signature num: "+field.getSignatures().length());
+
+        Encoder encoder=new Encoder();
+        encoder.encoderReset(new SizeT(Encoder.MaxPacketSize),new SizeT(0));
+        field.wireEncode(encoder);
+        byte[] buff=encoder.getBuffer();
+        Signature get=field.getSignatures().getElement(1);
+        System.out.println("sf buf: "+Arrays.toString(buff));
+        System.out.println("type: "+get.getSigInfo().getSignatureType().getValue().getSignatureAlgorithm());
+        System.out.println("keylocator: "+get.getSigInfo().getKeyLocator().getIdentifier().toUri());
+        System.out.println("value: "+ Arrays.toString(get.getSigValue().getValue()));
+
+        Block block=new Block(buff,false);
+        System.out.println(block.parseSubElements());
+        SignatureField field1=new SignatureField();
+        field1.wireDecode(block);
+        get=field1.getSignatures().getElement(1);
+        System.out.println("type: "+get.getSigInfo().getSignatureType().getValue().getSignatureAlgorithm());
+        System.out.println("keylocator: "+get.getSigInfo().getKeyLocator().getIdentifier().toUri());
+        System.out.println("value: "+ Arrays.toString(get.getSigValue().getValue()));
+
+        encoder.encoderReset(new SizeT(Encoder.MaxPacketSize),new SizeT(0));
+        field1.wireEncode(encoder);
+        byte[] buff1=encoder.getBuffer();
+        System.out.println("new buff: "+Arrays.toString(buff1));
+    }
+}