diff --git a/haobang-security-dm/syslog-serve/src/main/java/com/kafka/kafkaProducer.java b/haobang-security-dm/syslog-serve/src/main/java/com/kafka/kafkaProducer.java
index f0c267a..e1675bc 100644
--- a/haobang-security-dm/syslog-serve/src/main/java/com/kafka/kafkaProducer.java
+++ b/haobang-security-dm/syslog-serve/src/main/java/com/kafka/kafkaProducer.java
@@ -53,6 +53,7 @@ public class kafkaProducer {
                          @Value("${spring.kafka.producer.compression-type:lz4}") String compressionType,
                          @Value("${spring.kafka.producer.properties.max.block.ms:10000}") int maxBlockMs,
                          @Value("${spring.kafka.producer.properties.buffer.memory:134217728}") long bufferMemory,
+                         @Value("${spring.kafka.producer.properties.max.request.size:4194304}") int maxRequestSize,
                          @Value("${syslog.kafka.partition-key-strategy:event_id}") String partitionKeyStrategy) {
         this.appProperties = appProperties;
         this.partitionKeyStrategy = PartitionKeyStrategy.parse(partitionKeyStrategy);
@@ -73,12 +74,20 @@ public class kafkaProducer {
         // Dispatcher 已限制全局在途数；Producer 缓冲耗尽时快速返回失败，让事件留在 WAL 重试。
         props.put(ProducerConfig.MAX_BLOCK_MS_CONFIG, maxBlockMs);
         props.put(ProducerConfig.BUFFER_MEMORY_CONFIG, bufferMemory);
+        applyMaxRequestSize(props, maxRequestSize);
         // [SYSLOG-ALARM][KPROD][已修复] linger、batch 与压缩恢复跨消息批量能力，吞吐优化不改变 Broker ACK 边界。
         // [SYSLOG-ALARM][KPROD][已修复] Producer 只在应用启动时构造一次，单条热路径不再创建网络线程和连接。
         this.producer = new KafkaProducer<>(props);
         log.info("Kafka Producer 已启用分区策略: strategy={}", this.partitionKeyStrategy.configValue);
     }
 
+    static void applyMaxRequestSize(Properties props, int maxRequestSize) {
+        if (maxRequestSize <= 0) {
+            throw new IllegalArgumentException("spring.kafka.producer.properties.max.request.size 必须大于 0");
+        }
+        props.put(ProducerConfig.MAX_REQUEST_SIZE_CONFIG, maxRequestSize);
+    }
+
     /** 测试入口：复用真实的分区键选择和 ProducerRecord 构造逻辑，不建立 Kafka 网络连接。 */
     kafkaProducer(AppProperties appProperties, Producer<String, String> producer, String partitionKeyStrategy) {
         this.appProperties = appProperties;
diff --git a/haobang-security-dm/syslog-serve/src/main/resources/application.properties b/haobang-security-dm/syslog-serve/src/main/resources/application.properties
index 18ff490..d1fce49 100644
--- a/haobang-security-dm/syslog-serve/src/main/resources/application.properties
+++ b/haobang-security-dm/syslog-serve/src/main/resources/application.properties
@@ -86,6 +86,8 @@ spring.kafka.producer.properties.request.timeout.ms=30000
 spring.kafka.producer.properties.delivery.timeout.ms=120000
 spring.kafka.producer.properties.max.block.ms=10000
 spring.kafka.producer.properties.buffer.memory=134217728
+# 允许投递加密后超过 Kafka 默认 1 MiB 的 Syslog；Broker/Topic 上限必须不小于此值。
+spring.kafka.producer.properties.max.request.size=${KAFKA_PRODUCER_MAX_REQUEST_SIZE:4194304}
 # event_id 使高流量设备的独立事件均匀分布到多个分区；device_id 仅用于兼容回滚。
 syslog.kafka.partition-key-strategy=${SYSLOG_KAFKA_PARTITION_KEY_STRATEGY:event_id}
 
diff --git a/haobang-security-dm/syslog-serve/src/test/java/com/kafka/KafkaProducerEventIdTest.java b/haobang-security-dm/syslog-serve/src/test/java/com/kafka/KafkaProducerEventIdTest.java
index 8c8f2d0..cab9855 100644
--- a/haobang-security-dm/syslog-serve/src/test/java/com/kafka/KafkaProducerEventIdTest.java
+++ b/haobang-security-dm/syslog-serve/src/test/java/com/kafka/KafkaProducerEventIdTest.java
@@ -4,10 +4,12 @@ import com.haobang.config.AppProperties;
 import com.common.entity.DeviceDevice;
 import com.haobang.util.DeviceInfoUtil;
 import org.apache.kafka.clients.producer.Producer;
+import org.apache.kafka.clients.producer.ProducerConfig;
 import org.apache.kafka.clients.producer.ProducerRecord;
 import org.junit.jupiter.api.Test;
 
 import java.time.Instant;
+import java.util.Properties;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
@@ -17,6 +19,21 @@ import static org.mockito.Mockito.mock;
 
 class KafkaProducerEventIdTest {
 
+    @Test
+    void maxRequestSizeIsPassedToTheManuallyConstructedKafkaProducer() {
+        Properties properties = new Properties();
+
+        kafkaProducer.applyMaxRequestSize(properties, 4 * 1024 * 1024);
+
+        assertEquals(4 * 1024 * 1024, properties.get(ProducerConfig.MAX_REQUEST_SIZE_CONFIG));
+    }
+
+    @Test
+    void nonPositiveMaxRequestSizeFailsFast() {
+        assertThrows(IllegalArgumentException.class,
+                () -> kafkaProducer.applyMaxRequestSize(new Properties(), 0));
+    }
+
     @Test
     void eventIdDateUsesShanghaiTimeInsteadOfJvmDefaultTimeZone() {
         Instant shanghaiMidnight = Instant.parse("2026-08-10T16:00:00Z");