diff --git a/ess/ess-api/src/main/java/cn/axzo/nanopart/ess/api/request/CreateContractRequest.java b/ess/ess-api/src/main/java/cn/axzo/nanopart/ess/api/request/CreateContractRequest.java
index 4bdfaa48..05ccbee8 100644
--- a/ess/ess-api/src/main/java/cn/axzo/nanopart/ess/api/request/CreateContractRequest.java
+++ b/ess/ess-api/src/main/java/cn/axzo/nanopart/ess/api/request/CreateContractRequest.java
@@ -29,7 +29,7 @@ public abstract class CreateContractRequest {
      * 业务编码
      */
     @NotNull(message = "bizCode不能为空")
-    private String bizCode = "";
+    private String bizCode;
 
     /**
      * 幂等编码, 最大长度200. 使用appCode和idempotentCode的合同不能重复