diff --git a/heritage-model/src/main/java/org/leocoder/heritage/domain/model/vo/portal/EventRegistrationVo.java b/heritage-model/src/main/java/org/leocoder/heritage/domain/model/vo/portal/EventRegistrationVo.java
index a00370f..237ea85 100644
--- a/heritage-model/src/main/java/org/leocoder/heritage/domain/model/vo/portal/EventRegistrationVo.java
+++ b/heritage-model/src/main/java/org/leocoder/heritage/domain/model/vo/portal/EventRegistrationVo.java
@@ -12,10 +12,10 @@ import lombok.Data;
 public class EventRegistrationVo {
 
     /**
-     * 活动ID
+     * 活动ID（使用String避免前端JSON反序列化时的精度丢失）
      */
     @NotNull(message = "活动ID不能为空")
-    private Long eventId;
+    private String eventId;
 
     /**
      * 联系电话
diff --git a/heritage-modules/heritage-portal/src/main/java/org/leocoder/heritage/portal/controller/event/HrtEventController.java b/heritage-modules/heritage-portal/src/main/java/org/leocoder/heritage/portal/controller/event/HrtEventController.java
index 9702ade..1d5f3a6 100644
--- a/heritage-modules/heritage-portal/src/main/java/org/leocoder/heritage/portal/controller/event/HrtEventController.java
+++ b/heritage-modules/heritage-portal/src/main/java/org/leocoder/heritage/portal/controller/event/HrtEventController.java
@@ -62,7 +62,7 @@ public class HrtEventController {
     @Operation(summary = "取消报名", description = "取消已报名的活动，活动开始后无法取消")
     @PostMapping("/cancel/{eventId}")
     public String cancelRegistration(
-        @Parameter(description = "活动ID") @PathVariable Long eventId
+        @Parameter(description = "活动ID") @PathVariable String eventId
     ) {
         return hrtEventService.cancelRegistration(eventId);
     }
diff --git a/heritage-modules/heritage-portal/src/main/java/org/leocoder/heritage/portal/service/event/HrtEventService.java b/heritage-modules/heritage-portal/src/main/java/org/leocoder/heritage/portal/service/event/HrtEventService.java
index 9fd39ef..0b5a7b6 100644
--- a/heritage-modules/heritage-portal/src/main/java/org/leocoder/heritage/portal/service/event/HrtEventService.java
+++ b/heritage-modules/heritage-portal/src/main/java/org/leocoder/heritage/portal/service/event/HrtEventService.java
@@ -31,7 +31,7 @@ public interface HrtEventService {
      * @description [取消报名]
      * @author Leocoder
      */
-    String cancelRegistration(Long eventId);
+    String cancelRegistration(String eventId);
 
     /**
      * @description [我报名的活动]
diff --git a/heritage-modules/heritage-portal/src/main/java/org/leocoder/heritage/portal/service/event/HrtEventServiceImpl.java b/heritage-modules/heritage-portal/src/main/java/org/leocoder/heritage/portal/service/event/HrtEventServiceImpl.java
index 6393e48..5eec91c 100644
--- a/heritage-modules/heritage-portal/src/main/java/org/leocoder/heritage/portal/service/event/HrtEventServiceImpl.java
+++ b/heritage-modules/heritage-portal/src/main/java/org/leocoder/heritage/portal/service/event/HrtEventServiceImpl.java
@@ -158,9 +158,27 @@ public class HrtEventServiceImpl implements HrtEventService {
     public String registerEvent(EventRegistrationVo vo) {
         Long userId = HrtStpUtil.getLoginIdAsLong();
 
-        HrtEvent event = hrtEventMapper.selectById(vo.getEventId());
-        if (event == null || event.getPublishStatus() != 1) {
-            throw new BusinessException(404, "活动不存在或未发布");
+        // 参数校验
+        if (vo == null || vo.getEventId() == null || vo.getEventId().trim().isEmpty()) {
+            throw new BusinessException(400, "活动ID不能为空");
+        }
+
+        // 将String类型的eventId转换为Long（避免前端JSON精度丢失）
+        Long eventId;
+        try {
+            eventId = Long.parseLong(vo.getEventId());
+        } catch (NumberFormatException e) {
+            throw new BusinessException(400, "活动ID格式不正确");
+        }
+
+        // 查询活动
+        HrtEvent event = hrtEventMapper.selectById(eventId);
+        if (event == null) {
+            throw new BusinessException(404, "活动不存在(ID:" + eventId + ")");
+        }
+
+        if (event.getPublishStatus() != 1) {
+            throw new BusinessException(400, "活动未发布,无法报名");
         }
 
         if (!event.getStatus().equals("upcoming")) {
@@ -182,7 +200,7 @@ public class HrtEventServiceImpl implements HrtEventService {
 
         LambdaQueryWrapper<HrtEventRegistration> wrapper = new LambdaQueryWrapper<>();
         wrapper.eq(HrtEventRegistration::getUserId, userId)
-              .eq(HrtEventRegistration::getEventId, vo.getEventId())
+              .eq(HrtEventRegistration::getEventId, eventId)
               .in(HrtEventRegistration::getStatus, List.of("pending", "approved"));
         Long count = hrtEventRegistrationMapper.selectCount(wrapper);
         if (count > 0) {
@@ -195,7 +213,7 @@ public class HrtEventServiceImpl implements HrtEventService {
 
         HrtEventRegistration registration = new HrtEventRegistration();
         registration.setUserId(userId);
-        registration.setEventId(vo.getEventId());
+        registration.setEventId(eventId);
         registration.setStatus("approved");
         registration.setPhone(vo.getPhone());
         registration.setRemark(vo.getRemark());
@@ -208,7 +226,7 @@ public class HrtEventServiceImpl implements HrtEventService {
         hrtEventMapper.update(null,
             new LambdaUpdateWrapper<HrtEvent>()
                 .setSql("current_participants = current_participants + 1")
-                .eq(HrtEvent::getId, vo.getEventId())
+                .eq(HrtEvent::getId, eventId)
         );
 
         return "报名成功";
@@ -220,9 +238,22 @@ public class HrtEventServiceImpl implements HrtEventService {
      */
     @Override
     @Transactional(rollbackFor = Exception.class)
-    public String cancelRegistration(Long eventId) {
+    public String cancelRegistration(String eventIdStr) {
         Long userId = HrtStpUtil.getLoginIdAsLong();
 
+        // 参数校验
+        if (eventIdStr == null || eventIdStr.trim().isEmpty()) {
+            throw new BusinessException(400, "活动ID不能为空");
+        }
+
+        // 将String转换为Long（避免前端JSON精度丢失）
+        Long eventId;
+        try {
+            eventId = Long.parseLong(eventIdStr);
+        } catch (NumberFormatException e) {
+            throw new BusinessException(400, "活动ID格式不正确");
+        }
+
         LambdaQueryWrapper<HrtEventRegistration> wrapper = new LambdaQueryWrapper<>();
         wrapper.eq(HrtEventRegistration::getUserId, userId)
               .eq(HrtEventRegistration::getEventId, eventId)