diff --git a/src/main/java/com/budwk/app/zhgh/democratic/proposal/service/ProposalCaseCheckService.java b/src/main/java/com/budwk/app/zhgh/democratic/proposal/service/ProposalCaseCheckService.java
new file mode 100644
index 00000000..0adc1739
--- /dev/null
+++ b/src/main/java/com/budwk/app/zhgh/democratic/proposal/service/ProposalCaseCheckService.java
@@ -0,0 +1,17 @@
+package com.budwk.app.zhgh.democratic.proposal.service;
+
+import org.nutz.lang.util.NutMap;
+
+import java.util.List;
+
+public interface ProposalCaseCheckService {
+
+    /**
+     * 查询当前提案已经配置的承办单位。
+     * 二次答复只能从当前提案已有的主办/协办单位里选择，避免页面误选到无关单位。
+     *
+     * @param proposalId 提案ID
+     * @return 承办单位列表
+     */
+    List<NutMap> listReplyUnits(String proposalId);
+}
diff --git a/src/main/java/com/budwk/app/zhgh/democratic/proposal/service/impl/ProposalCaseCheckServiceImpl.java b/src/main/java/com/budwk/app/zhgh/democratic/proposal/service/impl/ProposalCaseCheckServiceImpl.java
new file mode 100644
index 00000000..3050c01d
--- /dev/null
+++ b/src/main/java/com/budwk/app/zhgh/democratic/proposal/service/impl/ProposalCaseCheckServiceImpl.java
@@ -0,0 +1,41 @@
+package com.budwk.app.zhgh.democratic.proposal.service.impl;
+
+import com.budwk.app.base.exception.BaseException;
+import com.budwk.app.zhgh.democratic.proposal.models.ProposalReplyUnit;
+import com.budwk.app.zhgh.democratic.proposal.service.ProposalCaseCheckService;
+import org.nutz.dao.Cnd;
+import org.nutz.dao.Dao;
+import org.nutz.ioc.loader.annotation.IocBean;
+import org.nutz.lang.util.NutMap;
+
+import java.util.List;
+
+@IocBean(args = {"refer:dao"})
+public class ProposalCaseCheckServiceImpl implements ProposalCaseCheckService {
+
+    private final Dao dao;
+
+    public ProposalCaseCheckServiceImpl(Dao dao) {
+        this.dao = dao;
+    }
+
+    @Override
+    public List<NutMap> listReplyUnits(String proposalId) {
+        if (proposalId == null || proposalId.isBlank()) {
+            throw new BaseException("提案ID不能为空");
+        }
+        /*
+         * 二次答复的承办单位来源于当前提案已落库的主办/协办配置。
+         * 这里按主办优先、再按单位名称排序，便于页面选择时直观看到主协办顺序。
+         */
+        List<ProposalReplyUnit> replyUnits = dao.query(ProposalReplyUnit.class,
+                Cnd.where(ProposalReplyUnit::getProposalId, "=", proposalId)
+                        .desc(ProposalReplyUnit::getIsMaster)
+                        .asc(ProposalReplyUnit::getUnitName));
+        return replyUnits.stream().map(replyUnit -> NutMap.NEW()
+                .setv("unitId", replyUnit.getUnitId())
+                .setv("unitName", replyUnit.getUnitName())
+                .setv("isMaster", replyUnit.getIsMaster())
+        ).toList();
+    }
+}