diff --git a/fe/fe-core/src/main/java/org/apache/doris/nereids/trees/expressions/functions/scalar/TimeDiff.java b/fe/fe-core/src/main/java/org/apache/doris/nereids/trees/expressions/functions/scalar/TimeDiff.java
index da83d5453f..997475ca40 100644
--- a/fe/fe-core/src/main/java/org/apache/doris/nereids/trees/expressions/functions/scalar/TimeDiff.java
+++ b/fe/fe-core/src/main/java/org/apache/doris/nereids/trees/expressions/functions/scalar/TimeDiff.java
@@ -21,10 +21,8 @@ import org.apache.doris.catalog.FunctionSignature;
 import org.apache.doris.nereids.trees.expressions.Expression;
 import org.apache.doris.nereids.trees.expressions.functions.ExplicitlyCastableSignature;
 import org.apache.doris.nereids.trees.expressions.functions.PropagateNullableOnDateLikeV2Args;
-import org.apache.doris.nereids.trees.expressions.literal.StringLikeLiteral;
 import org.apache.doris.nereids.trees.expressions.shape.BinaryExpression;
 import org.apache.doris.nereids.trees.expressions.visitor.ExpressionVisitor;
-import org.apache.doris.nereids.types.DataType;
 import org.apache.doris.nereids.types.DateTimeType;
 import org.apache.doris.nereids.types.DateTimeV2Type;
 import org.apache.doris.nereids.types.DateV2Type;
@@ -96,20 +94,4 @@ public class TimeDiff extends ScalarFunction
         }
         return signature;
     }
-
-    @Override
-    public List<DataType> expectedInputTypes() {
-        FunctionSignature signature = getSignature();
-        if (getArgument(0) instanceof StringLikeLiteral) {
-            StringLikeLiteral str = (StringLikeLiteral) getArgument(0);
-            DateTimeV2Type left = DateTimeV2Type.forTypeFromString(str.getStringValue());
-            signature = signature.withArgumentType(0, left);
-        }
-        if (getArgument(1) instanceof StringLikeLiteral) {
-            StringLikeLiteral str = (StringLikeLiteral) getArgument(1);
-            DateTimeV2Type right = DateTimeV2Type.forTypeFromString(str.getStringValue());
-            signature = signature.withArgumentType(1, right);
-        }
-        return signature.argumentsTypes;
-    }
 }
diff --git a/regression-test/data/correctness/test_time_diff_microseconds.out b/regression-test/data/correctness/test_time_diff_microseconds.out
index 2ef74548eb..39efa5b381 100644
--- a/regression-test/data/correctness/test_time_diff_microseconds.out
+++ b/regression-test/data/correctness/test_time_diff_microseconds.out
@@ -27,3 +27,6 @@
 -- !select8 --
 48:00:00.11500
 
+-- !select9 --
+67:19:00.123
+
diff --git a/regression-test/suites/correctness/test_time_diff_microseconds.groovy b/regression-test/suites/correctness/test_time_diff_microseconds.groovy
index a736820107..3dd023015f 100644
--- a/regression-test/suites/correctness/test_time_diff_microseconds.groovy
+++ b/regression-test/suites/correctness/test_time_diff_microseconds.groovy
@@ -91,4 +91,12 @@ suite("test_time_diff_microseconds") {
         cast('0001-01-03 00:00:00.114514' as Datetimev2(3) ) , 
         cast('0001-01-01 00:00:00.000000' as Datetimev2(5) ));
     """
+
+    sql """ 
+    select round(timediff(now(),'2024-08-15')/60/60,2);
+    """
+
+    qt_select9 """
+       select timediff('0001-01-03 19:19:00.123','0001-01-01 00:00:00.0000');
+    """
 }