diff --git a/src/test/java/xyz/zhouxy/jdbc/test/ParamBuilderTest.java b/src/test/java/xyz/zhouxy/jdbc/test/ParamBuilderTest.java
new file mode 100644
index 0000000..1c25988
--- /dev/null
+++ b/src/test/java/xyz/zhouxy/jdbc/test/ParamBuilderTest.java
@@ -0,0 +1,227 @@
+package xyz.zhouxy.jdbc.test;
+
+import static org.junit.jupiter.api.Assertions.*;
+import static xyz.zhouxy.jdbc.ParamBuilder.*;
+
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+import java.util.Optional;
+import java.util.OptionalDouble;
+import java.util.OptionalInt;
+import java.util.OptionalLong;
+import java.util.function.Function;
+
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+import xyz.zhouxy.jdbc.ParamBuilder;
+
+/**
+ * ParamBuilder 单元测试。
+ *
+ * <p>验证 {@code buildParams} 对各种 Optional 类型的拆箱处理，
+ * 以及 {@code buildBatchParams} 对集合的批量映射逻辑。</p>
+ *
+ * @see xyz.zhouxy.jdbc.ParamBuilder
+ */
+@DisplayName("ParamBuilder 参数构建测试")
+class ParamBuilderTest {
+
+    // ====================================================================
+    // #region - buildParams：空参数
+    // --------------------------------------------------------------------
+
+    @Test
+    @DisplayName("buildParams：无参 / null / 空数组均返回 EMPTY_OBJECT_ARRAY")
+    void testBuildParamsEmpty() {
+        assertSame(EMPTY_OBJECT_ARRAY, buildParams());
+        assertSame(EMPTY_OBJECT_ARRAY, buildParams((Object[]) null));
+        assertSame(EMPTY_OBJECT_ARRAY, buildParams(new Object[0]));
+    }
+
+    // --------------------------------------------------------------------
+    // #endregion
+    // ====================================================================
+
+    // ====================================================================
+    // #region - buildParams：普通参数
+    // --------------------------------------------------------------------
+
+    @Test
+    @DisplayName("buildParams：普通参数原样返回，null 元素保留（README 示例）")
+    void testBuildParamsPlain() {
+        Object[] result = buildParams("admin%", "0000", null, 100, 200L, 3.14, true);
+
+        assertEquals(7, result.length);
+        assertEquals("admin%", result[0]);
+        assertEquals("0000", result[1]);
+        assertNull(result[2]);
+        assertEquals(100, result[3]);
+        assertEquals(200L, result[4]);
+        assertEquals(3.14, result[5]);
+        assertEquals(true, result[6]);
+    }
+
+    // --------------------------------------------------------------------
+    // #endregion
+    // ====================================================================
+
+    // ====================================================================
+    // #region - buildParams：Optional<?>
+    // --------------------------------------------------------------------
+
+    @Test
+    @DisplayName("buildParams：Optional.of 拆箱为值，Optional.empty 拆箱为 null（README 示例）")
+    void testBuildParamsOptional() {
+        // README: Optional.of("hello") → "hello", Optional.empty() → null
+        Object[] result = buildParams(Optional.of("hello"), Optional.empty(), Optional.of(42));
+
+        assertEquals(3, result.length);
+        assertEquals("hello", result[0]);
+        assertNull(result[1]);
+        assertEquals(42, result[2]);
+    }
+
+    // --------------------------------------------------------------------
+    // #endregion
+    // ====================================================================
+
+    // ====================================================================
+    // #region - buildParams：OptionalInt / OptionalLong / OptionalDouble
+    // --------------------------------------------------------------------
+
+    @Test
+    @DisplayName("buildParams：OptionalInt.of → Integer，empty → null")
+    void testBuildParamsOptionalInt() {
+        Object[] result = buildParams(OptionalInt.of(42), OptionalInt.empty());
+
+        assertEquals(2, result.length);
+        assertEquals(42, result[0]);
+        assertInstanceOf(Integer.class, result[0]);
+        assertNull(result[1]);
+    }
+
+    @Test
+    @DisplayName("buildParams：OptionalLong.of → Long，empty → null")
+    void testBuildParamsOptionalLong() {
+        Object[] result = buildParams(OptionalLong.of(100L), OptionalLong.empty());
+
+        assertEquals(2, result.length);
+        assertEquals(100L, result[0]);
+        assertInstanceOf(Long.class, result[0]);
+        assertNull(result[1]);
+    }
+
+    @Test
+    @DisplayName("buildParams：OptionalDouble.of → Double，empty → null")
+    void testBuildParamsOptionalDouble() {
+        Object[] result = buildParams(OptionalDouble.of(3.14), OptionalDouble.empty());
+
+        assertEquals(2, result.length);
+        assertEquals(3.14, result[0]);
+        assertInstanceOf(Double.class, result[0]);
+        assertNull(result[1]);
+    }
+
+    // --------------------------------------------------------------------
+    // #endregion
+    // ====================================================================
+
+    // ====================================================================
+    // #region - buildParams：混合所有类型
+    // --------------------------------------------------------------------
+
+    @Test
+    @DisplayName("buildParams：混合所有 Optional + 普通类型 + null")
+    void testBuildParamsMixedAll() {
+        Object[] result = buildParams(
+                Optional.of("present"), Optional.empty(),
+                OptionalInt.of(10), OptionalInt.empty(),
+                OptionalLong.of(200L), OptionalLong.empty(),
+                OptionalDouble.of(1.5), OptionalDouble.empty(),
+                "plain", 999, null);
+
+        assertEquals(11, result.length);
+        assertEquals("present", result[0]);
+        assertNull(result[1]);
+        assertEquals(10, result[2]);
+        assertNull(result[3]);
+        assertEquals(200L, result[4]);
+        assertNull(result[5]);
+        assertEquals(1.5, result[6]);
+        assertNull(result[7]);
+        assertEquals("plain", result[8]);
+        assertEquals(999, result[9]);
+        assertNull(result[10]);
+    }
+
+    // --------------------------------------------------------------------
+    // #endregion
+    // ====================================================================
+
+    // ====================================================================
+    // #region - buildBatchParams
+    // --------------------------------------------------------------------
+
+    @Test
+    @DisplayName("buildBatchParams：集合映射为 List<Object[]>，配合 buildParams 使用（README 示例风格）")
+    void testBuildBatchParams() {
+        List<String[]> data = Arrays.asList(
+                new String[]{"admin", "123456", "0000"},
+                new String[]{"user1", "pass1", "0001"},
+                new String[]{"user2", "pass2", "0002"});
+
+        // README 风格: buildBatchParams(collection, item -> buildParams(...))
+        List<Object[]> result = buildBatchParams(data,
+                row -> buildParams(row[0], row[1], row[2]));
+
+        assertEquals(3, result.size());
+        assertArrayEquals(new Object[]{"admin", "123456", "0000"}, result.get(0));
+        assertArrayEquals(new Object[]{"user1", "pass1", "0001"}, result.get(1));
+        assertArrayEquals(new Object[]{"user2", "pass2", "0002"}, result.get(2));
+    }
+
+    @Test
+    @DisplayName("buildBatchParams：边界情况——空集合 / null collection / null func")
+    void testBuildBatchParamsBoundary() {
+        // 空集合返回 Collections.emptyList()
+        List<Object[]> emptyResult = buildBatchParams(Collections.emptyList(),
+                (Function<Object, Object[]>) obj -> new Object[]{obj});
+        assertTrue(emptyResult.isEmpty());
+        assertSame(Collections.emptyList(), emptyResult);
+
+        // null collection 抛异常
+        assertThrows(Exception.class, () ->
+                buildBatchParams(null, (Function<Object, Object[]>) obj -> new Object[]{obj}));
+
+        // null func 抛异常
+        assertThrows(Exception.class, () ->
+                buildBatchParams(Arrays.asList("a", "b"), null));
+    }
+
+    // --------------------------------------------------------------------
+    // #endregion
+    // ====================================================================
+
+    // ====================================================================
+    // #region - 私有构造器
+    // --------------------------------------------------------------------
+
+    @Test
+    @DisplayName("私有构造器抛 IllegalStateException")
+    void testPrivateConstructor() throws Exception {
+        java.lang.reflect.Constructor<ParamBuilder> ctor =
+                ParamBuilder.class.getDeclaredConstructor();
+        ctor.setAccessible(true);
+
+        java.lang.reflect.InvocationTargetException ex = assertThrows(
+                java.lang.reflect.InvocationTargetException.class, ctor::newInstance);
+        assertInstanceOf(IllegalStateException.class, ex.getCause());
+        assertEquals("Utility class", ex.getCause().getMessage());
+    }
+
+    // --------------------------------------------------------------------
+    // #endregion
+    // ====================================================================
+}