diff --git a/openhis-server-new/openhis-domain/src/main/java/com/openhis/clinical/mapper/OrderMapper.java b/openhis-server-new/openhis-domain/src/main/java/com/openhis/clinical/mapper/OrderMapper.java
index 5d106a20..6df707a4 100644
--- a/openhis-server-new/openhis-domain/src/main/java/com/openhis/clinical/mapper/OrderMapper.java
+++ b/openhis-server-new/openhis-domain/src/main/java/com/openhis/clinical/mapper/OrderMapper.java
@@ -44,10 +44,12 @@ public interface OrderMapper extends BaseMapper<Order> {
     int updatePayStatus(@Param("orderId") Long orderId, @Param("payStatus") Integer payStatus, @Param("payTime") Date payTime);
 
     /**
-     * 统计同一患者在同一科室、同一时段（上午/下午）内的有效预约订单数量
+     * 统计同一患者在同一科室、同一自然日（预约日 00:00～次日 00:00）内的有效预约订单数量。
+     * 匹配规则：优先 {@code department_id}（对应 adm_organization.id）；仅当 ID 为空时用 {@code department_name} 兜底。
      *
      * @param patientId 患者ID
-     * @param departmentId 科室ID
+     * @param departmentId 科室 ID（order_main.department_id）
+     * @param departmentName 科室名称（ID 为空时与 order_main.department_name 比对）
      * @param startTime 时段起始时间（含）
      * @param endTime 时段结束时间（不含）
      * @param statuses 订单状态集合（如 1=已预约,2=已取号）
@@ -55,6 +57,7 @@ public interface OrderMapper extends BaseMapper<Order> {
      */
     int countPatientDeptOrdersInPeriod(@Param("patientId") Long patientId,
         @Param("departmentId") Long departmentId,
+        @Param("departmentName") String departmentName,
         @Param("startTime") Date startTime,
         @Param("endTime") Date endTime,
         @Param("statuses") List<Integer> statuses);
diff --git a/openhis-server-new/openhis-domain/src/main/java/com/openhis/clinical/service/impl/TicketServiceImpl.java b/openhis-server-new/openhis-domain/src/main/java/com/openhis/clinical/service/impl/TicketServiceImpl.java
index 95bc8101..f48164a5 100644
--- a/openhis-server-new/openhis-domain/src/main/java/com/openhis/clinical/service/impl/TicketServiceImpl.java
+++ b/openhis-server-new/openhis-domain/src/main/java/com/openhis/clinical/service/impl/TicketServiceImpl.java
@@ -183,25 +183,23 @@ public class TicketServiceImpl extends ServiceImpl<TicketMapper, Ticket> impleme
             throw new RuntimeException("该排班医生已停诊");
         }
 
-        // 2.1 同一患者同一天/同一科室/同一时段（上午/下午）不可重复预约
-        if (dto.getPatientId() != null && slot.getDepartmentId() != null && slot.getScheduleDate() != null && slot.getExpectTime() != null) {
-            boolean isMorning = slot.getExpectTime().isBefore(LocalTime.NOON);
+        // 2.1 同一患者同一天/同一科室不可重复预约（自然日 00:00～次日 00:00，上午+下午共限 1 次；科室以 department_id 为准，无 ID 时用科室名兜底）
+        if (dto.getPatientId() != null && slot.getScheduleDate() != null
+                && (slot.getDepartmentId() != null
+                    || (slot.getDepartmentName() != null && !slot.getDepartmentName().isBlank()))) {
             LocalDate scheduleDateForCheck = slot.getScheduleDate();
-            LocalDateTime periodStart = isMorning
-                ? LocalDateTime.of(scheduleDateForCheck, LocalTime.MIN)
-                : LocalDateTime.of(scheduleDateForCheck, LocalTime.NOON);
-            LocalDateTime periodEnd = isMorning
-                ? LocalDateTime.of(scheduleDateForCheck, LocalTime.NOON)
-                : LocalDateTime.of(scheduleDateForCheck.plusDays(1), LocalTime.MIN);
+            LocalDateTime periodStart = LocalDateTime.of(scheduleDateForCheck, LocalTime.MIN);
+            LocalDateTime periodEnd = LocalDateTime.of(scheduleDateForCheck.plusDays(1), LocalTime.MIN);
 
             Date startTime = Date.from(periodStart.atZone(ZoneId.systemDefault()).toInstant());
             Date endTime = Date.from(periodEnd.atZone(ZoneId.systemDefault()).toInstant());
 
             // 预约去重以订单为准（order_main），因为预约成功会先落订单；clinical_ticket 不一定在此链路写入
             List<Integer> effectiveOrderStatuses = Arrays.asList(AppointmentOrderStatus.BOOKED, AppointmentOrderStatus.CHECKED_IN);
-            int exists = orderMapper.countPatientDeptOrdersInPeriod(dto.getPatientId(), slot.getDepartmentId(), startTime, endTime, effectiveOrderStatuses);
+            int exists = orderMapper.countPatientDeptOrdersInPeriod(dto.getPatientId(), slot.getDepartmentId(), slot.getDepartmentName(),
+                startTime, endTime, effectiveOrderStatuses);
             if (exists > 0) {
-                throw new RuntimeException("该患者已在当前科室该时段存在预约记录，不可重复预约");
+                throw new RuntimeException("该患者已在当前科室当日存在预约记录，不可重复预约");
             }
         }
 
diff --git a/openhis-server-new/openhis-domain/src/main/resources/mapper/clinical/OrderMapper.xml b/openhis-server-new/openhis-domain/src/main/resources/mapper/clinical/OrderMapper.xml
index c3212215..6bf5c677 100644
--- a/openhis-server-new/openhis-domain/src/main/resources/mapper/clinical/OrderMapper.xml
+++ b/openhis-server-new/openhis-domain/src/main/resources/mapper/clinical/OrderMapper.xml
@@ -222,7 +222,17 @@
         from order_main
         <where>
             and patient_id = #{patientId}
-            and department_id = #{departmentId}
+            <choose>
+                <when test="departmentId != null">
+                    and department_id = #{departmentId}
+                </when>
+                <when test="departmentName != null and departmentName != ''">
+                    and trim(department_name) = trim(#{departmentName})
+                </when>
+                <otherwise>
+                    and 1 = 0
+                </otherwise>
+            </choose>
             and appointment_time &gt;= #{startTime}
             and appointment_time &lt; #{endTime}
             <if test="statuses != null and statuses.size() &gt; 0">