diff --git a/Src/Asp.NetCore2/SqlSugar/Realization/Oracle/SqlBuilder/OracleUpdateBuilder.cs b/Src/Asp.NetCore2/SqlSugar/Realization/Oracle/SqlBuilder/OracleUpdateBuilder.cs
index daade0f47..85ba9d970 100644
--- a/Src/Asp.NetCore2/SqlSugar/Realization/Oracle/SqlBuilder/OracleUpdateBuilder.cs
+++ b/Src/Asp.NetCore2/SqlSugar/Realization/Oracle/SqlBuilder/OracleUpdateBuilder.cs
@@ -35,7 +35,7 @@ namespace SqlSugar
                 {
                     var isFirst = pkList.First() == item;
                     var whereString = isFirst ? " " : " AND ";
-                    whereString += GetOracleUpdateColums(item);
+                    whereString += GetOracleUpdateColums(item,true);
                     whereList.Add(whereString);
                 }
                 return string.Format("{0} {1} WHERE {2};", updateTable, setValues, string.Join("",whereList));
@@ -44,9 +44,15 @@ namespace SqlSugar
             return sb.ToString();
         }
 
-        private string GetOracleUpdateColums(DbColumnInfo m)
+        private string GetOracleUpdateColums(DbColumnInfo m,bool isWhere=false)
         {
-            return string.Format("\"{0}\"={1} ", m.DbColumnName.ToUpper(IsUppper), base.GetDbColumn(m,FormatValue(m.Value,m.IsPrimarykey,m.PropertyName)));
+
+            var result= string.Format("\"{0}\"={1} ", m.DbColumnName.ToUpper(IsUppper), base.GetDbColumn(m,FormatValue(m.Value,m.IsPrimarykey,m.PropertyName)));
+            if (isWhere&&m.Value == null) 
+            {
+                result = result.Replace("=NULL ", " is NULL ");
+            }
+            return result;
         }
         int i = 0;
         public  object FormatValue(object value,bool isPrimaryKey,string name)