diff --git a/pkg/config/sink.go b/pkg/config/sink.go
index aa755a65d8f..e959b9ebad5 100644
--- a/pkg/config/sink.go
+++ b/pkg/config/sink.go
@@ -221,14 +221,14 @@ func (c *CSVConfig) validateAndAdjust() error {
 	case 0:
 		return cerror.WrapError(cerror.ErrSinkInvalidConfig,
 			errors.New("csv config delimiter cannot be empty"))
-	case 1, 2:
+	case 1, 2, 3:
 		if strings.ContainsRune(c.Delimiter, CR) || strings.ContainsRune(c.Delimiter, LF) {
 			return cerror.WrapError(cerror.ErrSinkInvalidConfig,
 				errors.New("csv config delimiter contains line break characters"))
 		}
 	default:
 		return cerror.WrapError(cerror.ErrSinkInvalidConfig,
-			errors.New("csv config delimiter contains more than two character, note that escape "+
+			errors.New("csv config delimiter contains more than three characters, note that escape "+
 				"sequences can only be used in double quotes in toml configuration items."))
 	}
 
diff --git a/pkg/config/sink_test.go b/pkg/config/sink_test.go
index ccb606e92da..a0378f3c4d2 100644
--- a/pkg/config/sink_test.go
+++ b/pkg/config/sink_test.go
@@ -342,6 +342,15 @@ func TestValidateAndAdjustCSVConfig(t *testing.T) {
 			},
 			wantErr: "",
 		},
+		{
+			name: "valid delimiter with 3 characters",
+			config: &CSVConfig{
+				Quote:                "\"",
+				Delimiter:            "|@|",
+				BinaryEncodingMethod: BinaryEncodingHex,
+			},
+			wantErr: "",
+		},
 		{
 			name: "delimiter is empty",
 			config: &CSVConfig{
@@ -359,12 +368,12 @@ func TestValidateAndAdjustCSVConfig(t *testing.T) {
 			wantErr: "csv config delimiter contains line break characters",
 		},
 		{
-			name: "delimiter contains more than two characters",
+			name: "delimiter contains more than three characters",
 			config: &CSVConfig{
 				Quote:     "'",
-				Delimiter: "FEF",
+				Delimiter: "FEFA",
 			},
-			wantErr: "csv config delimiter contains more than two character, note that escape " +
+			wantErr: "csv config delimiter contains more than three characters, note that escape " +
 				"sequences can only be used in double quotes in toml configuration items.",
 		},
 		{