diff --git a/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/VisitorItems/BinaryExpressionTranslator/CalculationOperationExpression.cs b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/VisitorItems/BinaryExpressionTranslator/CalculationOperationExpression.cs
new file mode 100644
index 000000000..33355b402
--- /dev/null
+++ b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/VisitorItems/BinaryExpressionTranslator/CalculationOperationExpression.cs
@@ -0,0 +1,42 @@
+using MongoDB.Bson;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Linq.Expressions;
+using System.Text;
+
+namespace SqlSugar.MongoDb
+{
+    public partial class BinaryExpressionTranslator
+    { 
+        private BsonDocument GetCalculationOperation(BsonValue field, ExpressionType nodeType, BsonValue value, bool leftIsMember, bool rightIsMember)
+        {
+            string operation = GetCalculationType(nodeType);
+            if (IsStringAdd(value, operation))
+                return StringAddCalculation(field, value, leftIsMember, rightIsMember, out operation);
+            else
+                return GetCommonCalculation(field, value, operation);
+        } 
+        private static BsonDocument GetCommonCalculation(BsonValue field, BsonValue value, string operation)
+        {
+            return new BsonDocument
+            {
+                { field.ToString(), new BsonDocument { { operation, value } } }
+            };
+        }
+
+        private static BsonDocument StringAddCalculation(BsonValue field, BsonValue value, bool leftIsMember, bool rightIsMember, out string operation)
+        {
+            operation = "$concat";
+            return new BsonDocument
+                {
+                    { operation, new BsonArray { UtilMethods.GetBsonValue(leftIsMember, field), UtilMethods.GetBsonValue(rightIsMember, value) } }
+                };
+            ;
+        } 
+        private static bool IsStringAdd(BsonValue value, string operation)
+        {
+            return operation == "$add" && value.BsonType == BsonType.String;
+        }
+    }
+}
diff --git a/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/VisitorItems/BinaryExpressionTranslator/FieldComparisonExpression.cs b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/VisitorItems/BinaryExpressionTranslator/ComparisonOperationExpression.cs
similarity index 62%
rename from Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/VisitorItems/BinaryExpressionTranslator/FieldComparisonExpression.cs
rename to Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/VisitorItems/BinaryExpressionTranslator/ComparisonOperationExpression.cs
index e210f5047..b29def48f 100644
--- a/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/VisitorItems/BinaryExpressionTranslator/FieldComparisonExpression.cs
+++ b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/VisitorItems/BinaryExpressionTranslator/ComparisonOperationExpression.cs
@@ -8,15 +8,7 @@ using System.Text;
 namespace SqlSugar.MongoDb
 {
     public partial class BinaryExpressionTranslator
-    {
-        private BsonDocument FieldComparisonOrCalculationExpression(BinaryExpression expr)
-        {
-            OutParameters(expr, out var field, out var value, out var leftIsMember, out var rightIsMember, out var op);
-            return op == null
-                ? GetCalculationOperation(field, expr.NodeType, value, leftIsMember, rightIsMember)
-                : GetComparisonOperation(expr, field, value, leftIsMember, rightIsMember, op);
-        }
-
+    { 
         private BsonDocument GetComparisonOperation(BinaryExpression expr, BsonValue field, BsonValue value, bool leftIsMember, bool rightIsMember, string op)
         {
             string leftValue = "";
@@ -76,31 +68,5 @@ namespace SqlSugar.MongoDb
             }
         }
 
-        private BsonDocument GetCalculationOperation(BsonValue field, ExpressionType nodeType, BsonValue value, bool leftIsMember, bool rightIsMember)
-        {
-            string operation = nodeType switch
-            {
-                ExpressionType.Add => "$add",
-                ExpressionType.Subtract => "$subtract",
-                ExpressionType.Multiply => "$multiply",
-                ExpressionType.Divide => "$divide",
-                ExpressionType.Modulo => "$mod",
-                _ => throw new NotSupportedException($"Unsupported calculation operation: {nodeType}")
-            };
-            if (operation == "$add" && value.BsonType == BsonType.String)
-            {
-                operation = "$concat";
-                return new BsonDocument
-                {
-                    { operation, new BsonArray { UtilMethods.GetBsonValue(leftIsMember, field), UtilMethods.GetBsonValue(rightIsMember, value) } }
-                };
-                ;
-            }
-            return new BsonDocument
-            {
-                { field.ToString(), new BsonDocument { { operation, value } } }
-            };
-        }
-
     }
 }
diff --git a/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/VisitorItems/BinaryExpressionTranslator/FieldExpressionCase.cs b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/VisitorItems/BinaryExpressionTranslator/FieldExpressionCase.cs
new file mode 100644
index 000000000..1330bb767
--- /dev/null
+++ b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/VisitorItems/BinaryExpressionTranslator/FieldExpressionCase.cs
@@ -0,0 +1,20 @@
+using MongoDB.Bson;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Linq.Expressions;
+using System.Text;
+
+namespace SqlSugar.MongoDb
+{
+    public partial class BinaryExpressionTranslator
+    {
+        private BsonDocument FieldComparisonOrCalculationExpression(BinaryExpression expr)
+        {
+            OutParameters(expr, out var field, out var value, out var leftIsMember, out var rightIsMember, out var op);
+            return op == null
+                ? GetCalculationOperation(field, expr.NodeType, value, leftIsMember, rightIsMember)
+                : GetComparisonOperation(expr, field, value, leftIsMember, rightIsMember, op);
+        }
+    }
+}
diff --git a/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/VisitorItems/BinaryExpressionTranslator/Helper.cs b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/VisitorItems/BinaryExpressionTranslator/Helper.cs
index c21a30f7a..c931a5ac6 100644
--- a/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/VisitorItems/BinaryExpressionTranslator/Helper.cs
+++ b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/ExpToSql/VisitorItems/BinaryExpressionTranslator/Helper.cs
@@ -29,6 +29,19 @@ namespace SqlSugar.MongoDb
                 ExpressionType.LessThanOrEqual => "$lte",
                 _ => null
             };
-        } 
+        }
+         
+        private static string GetCalculationType(ExpressionType nodeType)
+        {
+            return nodeType switch
+            {
+                ExpressionType.Add => "$add",
+                ExpressionType.Subtract => "$subtract",
+                ExpressionType.Multiply => "$multiply",
+                ExpressionType.Divide => "$divide",
+                ExpressionType.Modulo => "$mod",
+                _ => throw new NotSupportedException($"Unsupported calculation operation: {nodeType}")
+            };
+        }
     }
 }