diff --git a/iotdb-api/pipe-api/src/main/java/org/apache/iotdb/pipe/api/type/Binary.java b/iotdb-api/pipe-api/src/main/java/org/apache/iotdb/pipe/api/type/Binary.java
index 3a878f58a62e7..3ea06382a15d0 100644
--- a/iotdb-api/pipe-api/src/main/java/org/apache/iotdb/pipe/api/type/Binary.java
+++ b/iotdb-api/pipe-api/src/main/java/org/apache/iotdb/pipe/api/type/Binary.java
@@ -72,7 +72,10 @@ public int compareTo(Binary other) {
         i++;
         continue;
       }
-      return this.values[i] - other.values[i];
+      // Compare the bytes as unsigned values so that the ordering matches the lexicographic
+      // (UTF-8 / memcmp) ordering used by TsFile and java.lang.String. A plain byte subtraction
+      // would treat bytes >= 0x80 as negative and sort them before ASCII bytes.
+      return (this.values[i] & 0xFF) - (other.values[i] & 0xFF);
     }
     return getLength() - other.getLength();
   }
diff --git a/iotdb-api/pipe-api/src/test/java/org/apache/iotdb/pipe/api/type/BinaryTest.java b/iotdb-api/pipe-api/src/test/java/org/apache/iotdb/pipe/api/type/BinaryTest.java
new file mode 100644
index 0000000000000..a8266ce0174fc
--- /dev/null
+++ b/iotdb-api/pipe-api/src/test/java/org/apache/iotdb/pipe/api/type/BinaryTest.java
@@ -0,0 +1,61 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.iotdb.pipe.api.type;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class BinaryTest {
+
+  @Test
+  public void compareToTreatsBytesAsUnsigned() {
+    // 0x41 ('A') is 65, 0x80 is 128 when read as an unsigned byte. The one with the larger
+    // unsigned value must sort after the smaller one.
+    final Binary low = new Binary(new byte[] {(byte) 0x41});
+    final Binary high = new Binary(new byte[] {(byte) 0x80});
+
+    Assert.assertTrue(low.compareTo(high) < 0);
+    Assert.assertTrue(high.compareTo(low) > 0);
+  }
+
+  @Test
+  public void compareToMatchesStringOrderingForNonAsciiText() {
+    // "é" is encoded as the two bytes 0xC3 0xA9 in UTF-8, so its first byte (195 unsigned) is
+    // greater than 'A' (65). The ordering must agree with java.lang.String ordering.
+    final Binary a = new Binary("A");
+    final Binary e = new Binary("é");
+
+    Assert.assertEquals("A".compareTo("é") < 0, a.compareTo(e) < 0);
+    Assert.assertTrue(a.compareTo(e) < 0);
+  }
+
+  @Test
+  public void compareToKeepsAsciiOrdering() {
+    Assert.assertTrue(new Binary("A").compareTo(new Binary("B")) < 0);
+    Assert.assertTrue(new Binary("abc").compareTo(new Binary("abd")) < 0);
+    Assert.assertEquals(0, new Binary("abc").compareTo(new Binary("abc")));
+  }
+
+  @Test
+  public void compareToUsesLengthWhenOneIsPrefixOfTheOther() {
+    Assert.assertTrue(new Binary("ab").compareTo(new Binary("abc")) < 0);
+    Assert.assertTrue(new Binary("abc").compareTo(new Binary("ab")) > 0);
+  }
+}
diff --git a/iotdb-api/udf-api/pom.xml b/iotdb-api/udf-api/pom.xml
index e90dd26be6c47..0f5177305d372 100644
--- a/iotdb-api/udf-api/pom.xml
+++ b/iotdb-api/udf-api/pom.xml
@@ -34,6 +34,11 @@
             <artifactId>common</artifactId>
             <version>${tsfile.version}</version>
         </dependency>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
     <build>
         <plugins>
diff --git a/iotdb-api/udf-api/src/main/java/org/apache/iotdb/udf/api/type/Binary.java b/iotdb-api/udf-api/src/main/java/org/apache/iotdb/udf/api/type/Binary.java
index e2b3ef857016a..7f3e10d61b5e7 100644
--- a/iotdb-api/udf-api/src/main/java/org/apache/iotdb/udf/api/type/Binary.java
+++ b/iotdb-api/udf-api/src/main/java/org/apache/iotdb/udf/api/type/Binary.java
@@ -72,7 +72,10 @@ public int compareTo(Binary other) {
         i++;
         continue;
       }
-      return this.values[i] - other.values[i];
+      // Compare the bytes as unsigned values so that the ordering matches the lexicographic
+      // (UTF-8 / memcmp) ordering used by TsFile and java.lang.String. A plain byte subtraction
+      // would treat bytes >= 0x80 as negative and sort them before ASCII bytes.
+      return (this.values[i] & 0xFF) - (other.values[i] & 0xFF);
     }
     return getLength() - other.getLength();
   }
diff --git a/iotdb-api/udf-api/src/test/java/org/apache/iotdb/udf/api/type/BinaryTest.java b/iotdb-api/udf-api/src/test/java/org/apache/iotdb/udf/api/type/BinaryTest.java
new file mode 100644
index 0000000000000..5309088838a22
--- /dev/null
+++ b/iotdb-api/udf-api/src/test/java/org/apache/iotdb/udf/api/type/BinaryTest.java
@@ -0,0 +1,61 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.iotdb.udf.api.type;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class BinaryTest {
+
+  @Test
+  public void compareToTreatsBytesAsUnsigned() {
+    // 0x41 ('A') is 65, 0x80 is 128 when read as an unsigned byte. The one with the larger
+    // unsigned value must sort after the smaller one.
+    final Binary low = new Binary(new byte[] {(byte) 0x41});
+    final Binary high = new Binary(new byte[] {(byte) 0x80});
+
+    Assert.assertTrue(low.compareTo(high) < 0);
+    Assert.assertTrue(high.compareTo(low) > 0);
+  }
+
+  @Test
+  public void compareToMatchesStringOrderingForNonAsciiText() {
+    // "é" is encoded as the two bytes 0xC3 0xA9 in UTF-8, so its first byte (195 unsigned) is
+    // greater than 'A' (65). The ordering must agree with java.lang.String ordering.
+    final Binary a = new Binary("A");
+    final Binary e = new Binary("é");
+
+    Assert.assertEquals("A".compareTo("é") < 0, a.compareTo(e) < 0);
+    Assert.assertTrue(a.compareTo(e) < 0);
+  }
+
+  @Test
+  public void compareToKeepsAsciiOrdering() {
+    Assert.assertTrue(new Binary("A").compareTo(new Binary("B")) < 0);
+    Assert.assertTrue(new Binary("abc").compareTo(new Binary("abd")) < 0);
+    Assert.assertEquals(0, new Binary("abc").compareTo(new Binary("abc")));
+  }
+
+  @Test
+  public void compareToUsesLengthWhenOneIsPrefixOfTheOther() {
+    Assert.assertTrue(new Binary("ab").compareTo(new Binary("abc")) < 0);
+    Assert.assertTrue(new Binary("abc").compareTo(new Binary("ab")) > 0);
+  }
+}