diff --git a/pqs-common/common-redis/src/main/java/com/njcn/redis/utils/RedisUtil.java b/pqs-common/common-redis/src/main/java/com/njcn/redis/utils/RedisUtil.java
index 23ec16594..fe9867018 100644
--- a/pqs-common/common-redis/src/main/java/com/njcn/redis/utils/RedisUtil.java
+++ b/pqs-common/common-redis/src/main/java/com/njcn/redis/utils/RedisUtil.java
@@ -347,6 +347,30 @@ public class RedisUtil {
         return info;
     }
 
+    /**
+     * 根据key模糊查询,并取出所有符合条件的key集合
+     * @return
+     */
+
+    public Set<String> scanKeysByPattern(String pattern, int count) {
+        Set<String> keys = new HashSet<>();
+        ScanOptions options = ScanOptions.scanOptions()
+                .match(pattern)
+                .count(count)
+                .build();
+
+        try (Cursor<byte[]> cursor = redisTemplate.getConnectionFactory()
+                .getConnection()
+                .scan(options)) {
+            while (cursor.hasNext()) {
+                keys.add(new String(cursor.next()));
+            }
+        } catch (Exception e) {
+            throw new RuntimeException("扫描Redis keys失败", e);
+        }
+        return keys;
+    }
+
     /**
      * 数据切库
      * @param dbIndex
diff --git a/pqs-event/event-common/src/main/java/com/njcn/event/common/service/EventAnalysisService.java b/pqs-event/event-common/src/main/java/com/njcn/event/common/service/EventAnalysisService.java
index 0ff99c5cd..e0145a95c 100644
--- a/pqs-event/event-common/src/main/java/com/njcn/event/common/service/EventAnalysisService.java
+++ b/pqs-event/event-common/src/main/java/com/njcn/event/common/service/EventAnalysisService.java
@@ -1,10 +1,10 @@
 package com.njcn.event.common.service;
 
 import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
-import com.njcn.event.pojo.param.*;
+import com.njcn.event.pojo.param.EventBaseParam;
+import com.njcn.event.pojo.param.StatisticsParam;
 import com.njcn.event.pojo.vo.*;
 
-import java.text.ParseException;
 import java.util.List;
 
 /**
@@ -79,8 +79,6 @@ public interface EventAnalysisService {
      */
     Page<WaveTypeVO> getMonitorEventAnalyseQuery(EventBaseParam eventBaseParam);
 
-
-
     /**
      *监测点事件波形下载
      * @author zbj
@@ -88,6 +86,20 @@ public interface EventAnalysisService {
      */
     //HttpServletResponse downloadMonitorEventWaveFile(WaveFileParam waveFileParam, HttpServletResponse response) throws Exception;
 
-
+    /**
+     * 判定压降落点区域
+     * <p>
+     * 入参：
+     *   eventValue  特征幅值（百分比形式，如 "80.5" 表示 80.5%），内部 /100 得到 VVm（0~1）
+     *   persistTime 持续时间（秒）
+     * <p>
+     * 优先规则：
+     *   1) 持续时间 < 0.001 秒 或 VVm = 0  →  A区
+     *   2) 按区间表逐行匹配（左闭右开 [下限, 上限)）
+     *   3) 都不匹配返回 null，由调用方走兜底
+     *
+     * @return 区域名（A区/B区/C区/D区）；解析失败或未匹配返回 null
+     */
+     String determineDropZone(String eventValue, String persistTime);
 
 }
diff --git a/pqs-event/event-common/src/main/java/com/njcn/event/common/service/impl/EventAnalysisServiceImpl.java b/pqs-event/event-common/src/main/java/com/njcn/event/common/service/impl/EventAnalysisServiceImpl.java
index 083200af6..6c332445f 100644
--- a/pqs-event/event-common/src/main/java/com/njcn/event/common/service/impl/EventAnalysisServiceImpl.java
+++ b/pqs-event/event-common/src/main/java/com/njcn/event/common/service/impl/EventAnalysisServiceImpl.java
@@ -4,7 +4,6 @@ import cn.hutool.core.bean.BeanUtil;
 import cn.hutool.core.collection.CollUtil;
 import cn.hutool.core.collection.CollectionUtil;
 import cn.hutool.core.date.DateUtil;
-import cn.hutool.core.util.StrUtil;
 import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
 import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
 import com.njcn.common.config.GeneralInfo;
@@ -13,6 +12,7 @@ import com.njcn.common.pojo.response.HttpResult;
 import com.njcn.device.pq.api.LineFeignClient;
 import com.njcn.device.pq.pojo.vo.AreaLineInfoVO;
 import com.njcn.device.pq.pojo.vo.LineDetailDataVO;
+import com.njcn.event.common.service.EventAnalysisService;
 import com.njcn.event.common.service.EventDetailService;
 import com.njcn.event.enums.EventResponseEnum;
 import com.njcn.event.file.pojo.enums.WaveFileResponseEnum;
@@ -21,19 +21,20 @@ import com.njcn.event.pojo.param.StatisticsParam;
 import com.njcn.event.pojo.po.EventDetail;
 import com.njcn.event.pojo.po.RmpEventDetailPO;
 import com.njcn.event.pojo.vo.*;
-import com.njcn.event.common.service.EventAnalysisService;
 import com.njcn.influx.utils.InfluxDbUtils;
 import com.njcn.system.api.DicDataFeignClient;
 import com.njcn.system.enums.DicDataEnum;
 import com.njcn.system.enums.DicDataTypeEnum;
 import com.njcn.system.pojo.po.DictData;
 import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
 import org.apache.commons.lang.StringUtils;
 import org.influxdb.dto.QueryResult;
 import org.springframework.stereotype.Service;
 
 import java.io.*;
-import java.text.ParseException;
+import java.math.BigDecimal;
+import java.math.RoundingMode;
 import java.time.LocalDate;
 import java.time.format.DateTimeFormatter;
 import java.time.temporal.ChronoUnit;
@@ -51,6 +52,7 @@ import java.util.zip.ZipOutputStream;
  */
 @Service
 @RequiredArgsConstructor
+@Slf4j
 public class EventAnalysisServiceImpl implements EventAnalysisService {
 
     // 定义阈值常量（单位：百分比）
@@ -1727,6 +1729,75 @@ public class EventAnalysisServiceImpl implements EventAnalysisService {
 
     }
 
+    @Override
+    public String determineDropZone(String eventValue, String persistTime) {
+        if (eventValue == null || eventValue.trim().isEmpty()
+                || persistTime == null || persistTime.trim().isEmpty()) {
+            log.warn("判定压降落点区域入参为空，eventValue={}, persistTime={}", eventValue, persistTime);
+            return null;
+        }
+        BigDecimal vvm;
+        BigDecimal vvtm;
+        try {
+            // params[3] 是百分比（如 "80.5"），/100 得到 0~1 的 VVm
+            vvm = new BigDecimal(eventValue.trim()).divide(new BigDecimal("100"), 6, RoundingMode.HALF_UP);
+            vvtm = new BigDecimal(persistTime.trim());
+        } catch (Exception e) {
+            log.error("判定压降落点区域入参解析失败，eventValue={}, persistTime={}", eventValue, persistTime, e);
+            return null;
+        }
+
+        // 1) 超短脉冲 或 完全失压 默认 A 区
+        if (vvtm.compareTo(new BigDecimal("0.001")) < 0
+                || vvm.compareTo(BigDecimal.ZERO) == 0) {
+            return "A区";
+        }
+
+        // 2) 区间表（左闭右开）
+        // A区
+        if (inRange(vvm, "0.9", "1") && inRange(vvtm, "0.001", "60")) {
+            return "A区";
+        }
+        if (inRange(vvm, "0", "0.9") && inRange(vvtm, "0.001", "0.05")) {
+            return "A区";
+        }
+        // B区
+        if (inRange(vvm, "0.5", "0.7") && inRange(vvtm, "0.05", "0.2")) {
+            return "B区";
+        }
+        if (inRange(vvm, "0.7", "0.8") && inRange(vvtm, "0.05", "0.5")) {
+            return "B区";
+        }
+        if (inRange(vvm, "0.8", "0.9") && inRange(vvtm, "0.05", "60")) {
+            return "B区";
+        }
+        // C区
+        if (inRange(vvm, "0", "0.5") && inRange(vvtm, "0.05", "1")) {
+            return "C区";
+        }
+        if (inRange(vvm, "0.5", "0.7") && inRange(vvtm, "0.2", "1")) {
+            return "C区";
+        }
+        if (inRange(vvm, "0.7", "0.8") && inRange(vvtm, "0.5", "1")) {
+            return "C区";
+        }
+        // D区
+        if (inRange(vvm, "0", "0.8") && inRange(vvtm, "1", "60")) {
+            return "D区";
+        }
+
+        log.warn("压降落点区域未匹配任何规则，eventValue={}, persistTime={}", eventValue, persistTime);
+        return null;
+    }
+
+    /**
+     * 左闭右开区间判断：lowerInclusive ≤ value < upperExclusive
+     */
+    private boolean inRange(BigDecimal value, String lowerInclusive, String upperExclusive) {
+        return value.compareTo(new BigDecimal(lowerInclusive)) >= 0
+                && value.compareTo(new BigDecimal(upperExclusive)) < 0;
+    }
+
 
     /**
      * 监测点事件波形下载