diff --git a/hutool-core/src/main/java/org/dromara/hutool/core/convert/RegisterConverter.java b/hutool-core/src/main/java/org/dromara/hutool/core/convert/RegisterConverter.java
index a3b7b94e1..77694dcc4 100644
--- a/hutool-core/src/main/java/org/dromara/hutool/core/convert/RegisterConverter.java
+++ b/hutool-core/src/main/java/org/dromara/hutool/core/convert/RegisterConverter.java
@@ -123,7 +123,8 @@ public class RegisterConverter implements Converter, Serializable {
 	 * @return 转换器
 	 */
 	public Converter getDefaultConverter(final Type type) {
-		return (null == defaultConverterMap) ? null : defaultConverterMap.get(TypeUtil.getClass(type));
+		final Class<?> key = null == type ? null : TypeUtil.getClass(type);
+		return (null == defaultConverterMap || null == key) ? null : defaultConverterMap.get(key);
 	}
 
 	/**
diff --git a/hutool-json/src/main/java/org/dromara/hutool/json/mapper/JSONValueMapper.java b/hutool-json/src/main/java/org/dromara/hutool/json/mapper/JSONValueMapper.java
index 981cbf407..d408d1f8f 100644
--- a/hutool-json/src/main/java/org/dromara/hutool/json/mapper/JSONValueMapper.java
+++ b/hutool-json/src/main/java/org/dromara/hutool/json/mapper/JSONValueMapper.java
@@ -171,6 +171,12 @@ public class JSONValueMapper {
 				return new JSONObject(object, jsonConfig);
 			}
 
+			// pr#3507
+			// Class类型保存类名
+			if (object instanceof Class) {
+				return ((Class<?>) object).getName();
+			}
+
 			// 枚举类保存其字符串形式（4.0.2新增）
 			if (object instanceof Enum
 				// Java内部类不做转换
diff --git a/hutool-json/src/test/java/org/dromara/hutool/json/Issue3504Test.java b/hutool-json/src/test/java/org/dromara/hutool/json/Issue3504Test.java
new file mode 100644
index 000000000..17bd0ac1f
--- /dev/null
+++ b/hutool-json/src/test/java/org/dromara/hutool/json/Issue3504Test.java
@@ -0,0 +1,24 @@
+package org.dromara.hutool.json;
+
+import lombok.Data;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+public class Issue3504Test {
+	@Test
+	public void test3504() {
+		final JsonBean jsonBean = new JsonBean();
+		jsonBean.setName("test");
+		jsonBean.setClasses(new Class[]{String.class});
+		final String huToolJsonStr = JSONUtil.toJsonStr(jsonBean);
+		final JsonBean bean = JSONUtil.toBean(huToolJsonStr, JsonBean.class);
+		Assertions.assertNotNull(bean);
+		Assertions.assertEquals("test", bean.getName());
+	}
+
+	@Data
+	public static class JsonBean {
+		private String name;
+		private Class<?>[] classes;
+	}
+}
diff --git a/hutool-json/src/test/java/org/dromara/hutool/json/Issue3506Test.java b/hutool-json/src/test/java/org/dromara/hutool/json/Issue3506Test.java
new file mode 100644
index 000000000..5c67a2cb0
--- /dev/null
+++ b/hutool-json/src/test/java/org/dromara/hutool/json/Issue3506Test.java
@@ -0,0 +1,30 @@
+package org.dromara.hutool.json;
+
+import lombok.Data;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+public class Issue3506Test {
+
+	@Test
+	void toBeanTest() {
+		final Languages languages = new Languages();
+		languages.setLanguageType(Java.class);
+
+		final String hutoolJSONString = JSONUtil.toJsonStr(languages);
+		final Languages bean = JSONUtil.toBean(hutoolJSONString, Languages.class);
+		Assertions.assertNotNull(bean);
+		Assertions.assertEquals(bean.getLanguageType(), Java.class);
+	}
+
+	@Data
+	public static class Languages {
+		private Class<? extends Language> languageType;
+	}
+
+	public interface Language {
+	}
+
+	public static class Java implements Language {
+	}
+}