diff --git a/CHANGELOG.md b/CHANGELOG.md
index c4b37e6d7..1f9c9c68f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,7 +3,7 @@
 
 -------------------------------------------------------------------------------------------------------------
 
-# 5.6.0 (2021-03-11)
+# 5.6.0 (2021-03-12)
 
 ### 新特性
 * 【poi    】     重要：不再兼容POI-3.x，增加兼容POI-5.x（issue#I35J6B@Gitee）
@@ -21,6 +21,8 @@
 * 【socket 】     修复Client创建失败资源未释放问题。
 * 【core   】     修复DataSizeUtil中EB单位错误问题（issue#I39O7I@Gitee）
 * 【core   】     修复BeanDesc.isMatchSetter的ignoreCase未使用问题（issue#I3AXIJ@Gitee）
+* 【core   】     修复CRC16Checksum中（issue#I3AXIJ@Gitee）
+* 【core   】     修复UrlQuery中对空key解析丢失问题（issue#I3B3J6@Gitee）
 
 -------------------------------------------------------------------------------------------------------------
 
diff --git a/hutool-core/src/main/java/cn/hutool/core/io/checksum/crc16/CRC16Checksum.java b/hutool-core/src/main/java/cn/hutool/core/io/checksum/crc16/CRC16Checksum.java
index 502614ecb..511dccf30 100644
--- a/hutool-core/src/main/java/cn/hutool/core/io/checksum/crc16/CRC16Checksum.java
+++ b/hutool-core/src/main/java/cn/hutool/core/io/checksum/crc16/CRC16Checksum.java
@@ -47,7 +47,7 @@ public abstract class CRC16Checksum implements Checksum, Serializable {
 	public String getHexValue(boolean isPadding){
 		String hex = HexUtil.toHex(getValue());
 		if(isPadding){
-			hex = StrUtil.padAfter(hex, 4, '0');
+			hex = StrUtil.padPre(hex, 4, '0');
 		}
 
 		return hex;
diff --git a/hutool-core/src/main/java/cn/hutool/core/net/url/UrlQuery.java b/hutool-core/src/main/java/cn/hutool/core/net/url/UrlQuery.java
index 232981999..62fa8e429 100644
--- a/hutool-core/src/main/java/cn/hutool/core/net/url/UrlQuery.java
+++ b/hutool-core/src/main/java/cn/hutool/core/net/url/UrlQuery.java
@@ -222,7 +222,7 @@ public class UrlQuery {
 				sb.append("&");
 			}
 			key = entry.getKey();
-			if (StrUtil.isNotEmpty(key)) {
+			if (null != key) {
 				sb.append(URLUtil.encodeAll(StrUtil.str(key), charset));
 				value = entry.getValue();
 				if (null != value) {
diff --git a/hutool-core/src/test/java/cn/hutool/core/io/checksum/CrcTest.java b/hutool-core/src/test/java/cn/hutool/core/io/checksum/CrcTest.java
index b7f33f13b..ccdcc6aba 100644
--- a/hutool-core/src/test/java/cn/hutool/core/io/checksum/CrcTest.java
+++ b/hutool-core/src/test/java/cn/hutool/core/io/checksum/CrcTest.java
@@ -1,12 +1,14 @@
 package cn.hutool.core.io.checksum;
 
+import cn.hutool.core.io.checksum.crc16.CRC16XModem;
 import cn.hutool.core.util.HexUtil;
+import cn.hutool.core.util.StrUtil;
 import org.junit.Assert;
 import org.junit.Test;
 
 /**
  * CRC校验单元测试
- * 
+ *
  * @author looly
  *
  */
@@ -40,4 +42,14 @@ public class CrcTest {
 		String crc16 = HexUtil.toHex(crc.getValue());
 		Assert.assertEquals("18c", crc16);
 	}
+
+	@Test
+	public void paddingTest(){
+		// I3B3RV@Gitee
+		String text = "000123FFFFFF";
+		CRC16XModem crc16 = new CRC16XModem();
+		crc16.update(StrUtil.bytes(text));
+		String hexValue = crc16.getHexValue(true);
+		Assert.assertEquals("0e04", hexValue);
+	}
 }
diff --git a/hutool-core/src/test/java/cn/hutool/core/net/UrlQueryTest.java b/hutool-core/src/test/java/cn/hutool/core/net/UrlQueryTest.java
index 58c84e929..285661c1f 100644
--- a/hutool-core/src/test/java/cn/hutool/core/net/UrlQueryTest.java
+++ b/hutool-core/src/test/java/cn/hutool/core/net/UrlQueryTest.java
@@ -26,4 +26,12 @@ public class UrlQueryTest {
 		final String queryStr = urlBuilder.getQueryStr();
 		Assert.assertEquals("imageMogr2/auto-orient/thumbnail/500&pid=259848", queryStr);
 	}
+
+	@Test
+	public void parseTest2(){
+		String requestUrl = "http://192.168.1.1:8080/pc?=d52i5837i4ed=o39-ap9e19s5--=72e54*ll0lodl-f338868d2";
+		UrlQuery q = new UrlQuery();
+		UrlQuery parse = q.parse(requestUrl, Charset.defaultCharset());
+		Assert.assertEquals("=d52i5837i4ed=o39-ap9e19s5--=72e54*ll0lodl-f338868d2", parse.toString());
+	}
 }