diff --git a/src/main/java/com/rj/dto/hxr/HxrSimpleApiResponse.java b/src/main/java/com/rj/dto/hxr/HxrSimpleApiResponse.java
new file mode 100644
index 0000000..d2ff98e
--- /dev/null
+++ b/src/main/java/com/rj/dto/hxr/HxrSimpleApiResponse.java
@@ -0,0 +1,4 @@
+package com.rj.dto.hxr;
+
+/** hxrd 后台部分写接口通用 {@code code/msg} 响应。 */
+public record HxrSimpleApiResponse(int code, String msg) {}
diff --git a/src/main/java/com/rj/dto/hxr/HxrUserRow.java b/src/main/java/com/rj/dto/hxr/HxrUserRow.java
new file mode 100644
index 0000000..1d6f667
--- /dev/null
+++ b/src/main/java/com/rj/dto/hxr/HxrUserRow.java
@@ -0,0 +1,6 @@
+package com.rj.dto.hxr;
+
+/**
+ * hxrd 后台 {@code /app/admin/user/select} 列表项（仅声明更新所需字段，其余字段忽略）。
+ */
+public record HxrUserRow(Long id) {}
diff --git a/src/main/java/com/rj/dto/hxr/HxrUserSelectResponse.java b/src/main/java/com/rj/dto/hxr/HxrUserSelectResponse.java
new file mode 100644
index 0000000..11e35c8
--- /dev/null
+++ b/src/main/java/com/rj/dto/hxr/HxrUserSelectResponse.java
@@ -0,0 +1,6 @@
+package com.rj.dto.hxr;
+
+import java.util.List;
+
+/** hxrd 后台 {@code /app/admin/user/select} 顶层 JSON。 */
+public record HxrUserSelectResponse(int code, String msg, int count, List<HxrUserRow> data) {}
diff --git a/src/main/java/com/rj/service/HxrAdminUserService.java b/src/main/java/com/rj/service/HxrAdminUserService.java
new file mode 100644
index 0000000..bd8be1e
--- /dev/null
+++ b/src/main/java/com/rj/service/HxrAdminUserService.java
@@ -0,0 +1,201 @@
+package com.rj.service;
+
+import com.fasterxml.jackson.databind.DeserializationFeature;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.PropertyNamingStrategies;
+import com.rj.config.HxrAdminProperties;
+import com.rj.dto.hxr.HxrSimpleApiResponse;
+import com.rj.dto.hxr.HxrUserRow;
+import com.rj.dto.hxr.HxrUserSelectResponse;
+import com.rj.util.IsoWorkdayUtils;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.stereotype.Service;
+import org.springframework.web.util.UriComponentsBuilder;
+
+import java.net.URI;
+import java.net.URLEncoder;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+import java.nio.charset.StandardCharsets;
+import java.time.LocalDate;
+import java.time.LocalDateTime;
+import java.time.format.DateTimeFormatter;
+import java.util.List;
+import java.util.Optional;
+
+/**
+ * 调用 hxrd 后台用户查询、更新接口（与 {@link HxrAdminOrderSelectService} 共用 {@link HxrAdminProperties} 会话）。
+ */
+@Slf4j
+@Service
+@RequiredArgsConstructor
+public class HxrAdminUserService {
+
+    private static final ObjectMapper JSON = new ObjectMapper()
+            .setPropertyNamingStrategy(PropertyNamingStrategies.SNAKE_CASE)
+            .configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
+
+    private static final DateTimeFormatter VIP_TIME_FORMAT =
+            DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
+
+    private final HxrAdminProperties properties;
+
+    /**
+     * VIP 到期时间：以 {@code applyDate} 为起算日，若当天为周六、周日则先顺延到下一工作日，再顺延 2 个工作日；
+     * 时刻与调用时「当前时刻」的时分秒相同（仅调整日期）。
+     */
+    public static LocalDateTime computeVipExpireTime(LocalDate applyDate) {
+        if (applyDate == null) {
+            throw new IllegalArgumentException("applyDate不能为空");
+        }
+        LocalDateTime now = LocalDateTime.now();
+        LocalDate d = applyDate;
+        while (IsoWorkdayUtils.isWeekend(d)) {
+            d = d.plusDays(1);
+        }
+        for (int i = 0; i < 2; i++) {
+            d = d.plusDays(1);
+            while (IsoWorkdayUtils.isWeekend(d)) {
+                d = d.plusDays(1);
+            }
+        }
+        return LocalDateTime.of(d, now.toLocalTime());
+    }
+
+    /**
+     * 调用第三方接口
+     * 按手机号查询用户列表，返回第一条。
+     */
+    public Optional<HxrUserRow> fetchFirstUserByMobile(String mobile) throws Exception {
+        String cookieHeader = properties.resolveCookieHeader();
+        if (cookieHeader == null || cookieHeader.isBlank()) {
+            log.warn("hxr.admin 未配置 cookie 或 phpsid，跳过 user/select");
+            return Optional.empty();
+        }
+        if (mobile == null || mobile.isBlank()) {
+            return Optional.empty();
+        }
+
+        String uri = UriComponentsBuilder.fromUriString(properties.getUserSelectUrl())
+                .replaceQueryParam("mobile", mobile.trim())
+                .replaceQueryParam("id", "")
+                .replaceQueryParam("pid", "")
+                .build()
+                .encode()
+                .toUriString();
+
+        HttpClient client = HttpClient.newBuilder()
+                .connectTimeout(java.time.Duration.ofSeconds(35))
+                .followRedirects(HttpClient.Redirect.NORMAL)
+                .build();
+
+        HttpRequest request = HttpRequest.newBuilder()
+                .uri(URI.create(uri))
+                .timeout(java.time.Duration.ofSeconds(120))
+                .header("Accept", "application/json, text/javascript, */*; q=0.01")
+                .header("Accept-Language", "zh-CN,zh;q=0.9,en;q=0.8,en-GB;q=0.7,en-US;q=0.6")
+                .header("Cookie", cookieHeader)
+                .header("Priority", "u=1, i")
+                .header("Referer", "https://hxrdhoutai.hxrdsm.cn/app/admin/user/index")
+                .header("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/148.0.0.0 Safari/537.36 Edg/148.0.0.0")
+                .GET()
+                .build();
+
+        HttpResponse<String> response = client.send(request, HttpResponse.BodyHandlers.ofString());
+        int status = response.statusCode();
+        if (status < 200 || status >= 300) {
+            log.warn("hxr admin user/select HTTP {} mobile={} bodyPrefix={}",
+                    status, mobile, abbreviate(response.body(), 400));
+            return Optional.empty();
+        }
+
+        HxrUserSelectResponse body = JSON.readValue(response.body(), HxrUserSelectResponse.class);
+        if (body.code() != 0) {
+            log.warn("hxr admin user/select api code={} msg={} mobile={}", body.code(), body.msg(), mobile);
+            return Optional.empty();
+        }
+        List<HxrUserRow> data = body.data();
+        if (data == null || data.isEmpty()) {
+            return Optional.empty();
+        }
+        HxrUserRow first = data.get(0);
+        if (first.id() == null) {
+            return Optional.empty();
+        }
+        return Optional.of(first);
+    }
+
+    /**
+     * 更新用户 VIP 相关字段（{@code application/x-www-form-urlencoded}）。
+     *
+     * @return 接口 {@code code==0} 时为 true
+     */
+    public boolean updateUserVipFields(long userId, int maxOrder, String viptimeFormatted) throws Exception {
+        String cookieHeader = properties.resolveCookieHeader();
+        if (cookieHeader == null || cookieHeader.isBlank()) {
+            log.warn("hxr.admin 未配置 cookie 或 phpsid，跳过 user/update");
+            return false;
+        }
+
+        String form = buildUpdateFormBody(userId, maxOrder, viptimeFormatted);
+
+        HttpClient client = HttpClient.newBuilder()
+                .connectTimeout(java.time.Duration.ofSeconds(35))
+                .followRedirects(HttpClient.Redirect.NORMAL)
+                .build();
+
+        HttpRequest request = HttpRequest.newBuilder()
+                .uri(URI.create(properties.getUserUpdateUrl()))
+                .timeout(java.time.Duration.ofSeconds(120))
+                .header("Accept", "application/json, text/javascript, */*; q=0.01")
+                .header("Content-Type", "application/x-www-form-urlencoded; charset=UTF-8")
+                .header("Cookie", cookieHeader)
+                .header("Referer", "https://hxrdhoutai.hxrdsm.cn/app/admin/user/index")
+                .header("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/148.0.0.0 Safari/537.36 Edg/148.0.0.0")
+                .POST(HttpRequest.BodyPublishers.ofString(form, StandardCharsets.UTF_8))
+                .build();
+
+        HttpResponse<String> response = client.send(request, HttpResponse.BodyHandlers.ofString());
+        int status = response.statusCode();
+        if (status < 200 || status >= 300) {
+            log.warn("hxr admin user/update HTTP {} id={} bodyPrefix={}",
+                    status, userId, abbreviate(response.body(), 400));
+            return false;
+        }
+
+        try {
+            HxrSimpleApiResponse api = JSON.readValue(response.body(), HxrSimpleApiResponse.class);
+            if (api.code() != 0) {
+                log.warn("hxr admin user/update api code={} msg={} id={}", api.code(), api.msg(), userId);
+                return false;
+            }
+            return true;
+        } catch (Exception e) {
+            log.warn("hxr admin user/update parse body id={} err={} bodyPrefix={}",
+                    userId, e.getMessage(), abbreviate(response.body(), 400));
+            return false;
+        }
+    }
+
+    public static String formatVipTime(LocalDateTime t) {
+        return t.format(VIP_TIME_FORMAT);
+    }
+
+    private static String buildUpdateFormBody(long userId, int maxOrder, String viptimeFormatted) {
+        return "id=" + userId
+                + "&max_order=" + maxOrder
+                + "&is_vip=1"
+                + "&is_resell=1"
+                + "&status=1"
+                + "&viptime=" + URLEncoder.encode(viptimeFormatted, StandardCharsets.UTF_8);
+    }
+
+    private static String abbreviate(String s, int maxLen) {
+        if (s == null) {
+            return "";
+        }
+        return s.length() <= maxLen ? s : s.substring(0, maxLen) + "...";
+    }
+}