diff --git a/package-lock.json b/package-lock.json
index 5c2cdf2..9be3781 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1756,6 +1756,11 @@
       "resolved": "https://registry.npmjs.org/chardet/-/chardet-0.4.2.tgz",
       "integrity": "sha1-tUc7M9yXxCTl2Y3IfVXU2KKci/I="
     },
+    "charenc": {
+      "version": "0.0.2",
+      "resolved": "http://registry.npm.taobao.org/charenc/download/charenc-0.0.2.tgz",
+      "integrity": "sha1-wKHS86cJLgN3S/qD8UwPxXkKhmc="
+    },
     "chokidar": {
       "version": "2.0.4",
       "resolved": "https://registry.npmjs.org/chokidar/-/chokidar-2.0.4.tgz",
@@ -2216,6 +2221,11 @@
         "which": "1.3.1"
       }
     },
+    "crypt": {
+      "version": "0.0.2",
+      "resolved": "http://registry.npm.taobao.org/crypt/download/crypt-0.0.2.tgz",
+      "integrity": "sha1-iNf/fsDfuG9xPch7u0LQRNPmxBs="
+    },
     "crypto-browserify": {
       "version": "3.12.0",
       "resolved": "https://registry.npmjs.org/crypto-browserify/-/crypto-browserify-3.12.0.tgz",
@@ -6562,6 +6572,16 @@
       "resolved": "https://registry.npmjs.org/math-random/-/math-random-1.0.1.tgz",
       "integrity": "sha1-izqsWIuKZuSXXjzepn97sylgH6w="
     },
+    "md5": {
+      "version": "2.2.1",
+      "resolved": "http://registry.npm.taobao.org/md5/download/md5-2.2.1.tgz",
+      "integrity": "sha1-U6s41f48iJG6RlMp6iP6wFQBJvk=",
+      "requires": {
+        "charenc": "0.0.2",
+        "crypt": "0.0.2",
+        "is-buffer": "1.1.6"
+      }
+    },
     "md5.js": {
       "version": "1.3.4",
       "resolved": "https://registry.npmjs.org/md5.js/-/md5.js-1.3.4.tgz",
diff --git a/package.json b/package.json
index 073f7f4..3b3fdc4 100644
--- a/package.json
+++ b/package.json
@@ -5,6 +5,7 @@
   "dependencies": {
     "copy-to-clipboard": "^3.0.8",
     "load-script": "^1.0.0",
+    "md5": "^2.2.1",
     "pressure": "^2.1.2",
     "react": "^16.4.2",
     "react-dom": "^16.4.2",
diff --git a/src/App.js b/src/App.js
index 3d465ff..474415b 100644
--- a/src/App.js
+++ b/src/App.js
@@ -5,6 +5,20 @@ import {Sidebar} from './Sidebar';
 import {PressureHelper} from './PressureHelper';
 import {TokenCtx} from './UserAction';
 
+function TokenDeprecatedAlert(props) {
+    if(!props.token || props.token.startsWith('isop_')) // noinspection JSConstructorReturnsPrimitive
+            return null;
+    else
+        return (
+            <div className="flow-item-row">
+                <div className="box box-tip flow-item box-danger">
+                    <p>树洞已更换登录方式，您原来的登录状态已失效。</p>
+                    <p>请按右上角的按钮，点“注销”，然后重新登录。</p>
+                </div>
+            </div>
+        );
+}
+
 class App extends Component {
     constructor(props) {
         super(props);
@@ -62,14 +76,15 @@ class App extends Component {
                     backgroundImage: 'url('+(localStorage['REPLACE_ERIRI_WITH_URL'] || 'static/eriri_bg.jpg')+')'
                 }} />
                 <Title show_sidebar={this.show_sidebar_bound} set_mode={this.set_mode_bound} />
-                <div className="left-container">
-                    <TokenCtx.Consumer>{(token)=>(
+                <TokenCtx.Consumer>{(token)=>(
+                    <div className="left-container">
+                        <TokenDeprecatedAlert token={token.value} />
                         <Flow key={this.state.flow_render_key} show_sidebar={this.show_sidebar_bound}
                               mode={this.state.mode} search_text={this.state.search_text} token={token.value}
                         />
-                    )}</TokenCtx.Consumer>
-                    <br />
-                </div>
+                        <br />
+                    </div>
+                )}</TokenCtx.Consumer>
                 <Sidebar do_close={()=>{
                     this.setState({
                         sidebar_content: null,
diff --git a/src/Flows.js b/src/Flows.js
index 799710f..7297b40 100644
--- a/src/Flows.js
+++ b/src/Flows.js
@@ -341,14 +341,16 @@ function FlowChunk(props) {
                 {!!props.title && <TitleLine text={props.title} />}
                 {props.list.map((info,ind)=>(
                     <LazyLoad key={info.pid} offset={500} height="15em" once={true} >
-                        {!!(props.deletion_detect && props.mode==='list' && ind && props.list[ind-1].pid-info.pid>1) &&
-                            <div className="flow-item-row">
-                                <div className="box box-tip flow-item box-danger">
-                                    {props.list[ind-1].pid-info.pid-1} 条被删除
+                        <div>
+                            {!!(props.deletion_detect && props.mode==='list' && ind && props.list[ind-1].pid-info.pid>1) &&
+                                <div className="flow-item-row">
+                                    <div className="box box-tip flow-item box-danger">
+                                        {props.list[ind-1].pid-info.pid-1} 条被删除
+                                    </div>
                                 </div>
-                            </div>
-                        }
-                        <FlowItemRow info={info} show_sidebar={props.show_sidebar} token={token} />
+                            }
+                            <FlowItemRow info={info} show_sidebar={props.show_sidebar} token={token} />
+                        </div>
                     </LazyLoad>
                 ))}
             </div>
diff --git a/src/UserAction.css b/src/UserAction.css
index 7908ab2..e9d4cb0 100644
--- a/src/UserAction.css
+++ b/src/UserAction.css
@@ -1,4 +1,4 @@
-.login-form form p {
+.login-form p {
     margin: 1em 0;
     text-align: center;
 }
diff --git a/src/UserAction.js b/src/UserAction.js
index 87c84a3..ce7a8dd 100644
--- a/src/UserAction.js
+++ b/src/UserAction.js
@@ -1,5 +1,6 @@
 import React, {Component, PureComponent} from 'react';
 import {SafeTextarea} from './Common';
+import md5 from 'md5';
 
 import './UserAction.css';
 
@@ -8,6 +9,10 @@ const LOGIN_BASE=window.location.protocol==='https:' ? '/login_proxy' : 'http://
 const MAX_IMG_PX=2000;
 const MAX_IMG_FILESIZE=256000;
 
+const ISOP_APPKEY='0feb3a8a831e11e8933a0050568508a5';
+const ISOP_APPCODE='0fec960a831e11e8933a0050568508a5';
+const ISOP_SVCID='PERSON_BASE_INFO,STUDENT_SCORE,STUDENT_COURSE_TABLE,STUDENT_COURSE_TABLE_ROOM,CARD_BALANCE';
+
 export const TokenCtx=React.createContext({
     value: null,
     set_value: ()=>{},
@@ -24,8 +29,25 @@ export class LoginForm extends Component {
         this.password_ref=React.createRef();
     }
 
-    do_login(event,set_token) {
-        event.preventDefault();
+    do_sendcode() {
+        if(this.state.loading_status==='loading')
+            return;
+
+        let param=
+            'user='+this.username_ref.current.value+
+            '&svcId='+ISOP_SVCID+
+            '&appKey='+ISOP_APPKEY+
+            '&timestamp='+(+new Date());
+
+        fetch(
+            'https://isop.pku.edu.cn/svcpub/svc/oauth/validcode?'+param+
+            '&msg='+md5(param+ISOP_APPCODE),
+            {mode: 'no-cors'}
+        );
+        alert('短信验证码应该会发到您的手机上，请注意查收！');
+    }
+
+    do_login(set_token) {
         if(this.state.loading_status==='loading')
             return;
 
@@ -33,8 +55,9 @@ export class LoginForm extends Component {
             loading_status: 'loading',
         });
         let data=new URLSearchParams();
-        data.append('uid', this.username_ref.current.value);
-        data.append('password', this.password_ref.current.value);
+        data.append('username', this.username_ref.current.value);
+        data.append('valid_code', this.password_ref.current.value);
+        data.append('isnewloginflow', 'true');
         fetch(LOGIN_BASE+'/login.php?platform=hole_xmcp_ml', {
             method: 'POST',
             headers: {
@@ -68,44 +91,43 @@ export class LoginForm extends Component {
         return (
             <TokenCtx.Consumer>{(token)=>
                 <div className="login-form box">
-                    <form onSubmit={(e)=>this.do_login(e,token.set_value)}>
-                        {token.value ?
+                    {token.value ?
+                        <div>
+                            <p>
+                                <b>您已登录。</b>
+                                <button type="button" onClick={()=>{token.set_value(null);}}>注销</button>
+                            </p>
                             <p>
-                                <b>您已登录。</b>Token: <code>{token.value||'(null)'}</code> <br />
+                                Token: <code>{token.value||'(null)'}</code> <br />
                                 请勿泄露 Token，它代表您的登录状态，与您的账户唯一对应且泄露后无法重置
-                            </p> :
-                            <p>登录后可以使用关注、回复等功能</p>
-                        }
-                        <p>
-                            <label>
-                                学号：
-                                <input ref={this.username_ref} type="tel" />
-                            </label>
-                        </p>
-                        <p>
-                            <label>
-                                密码：
-                                <input ref={this.password_ref} type="password" />
-                            </label>
-                        </p>
-                        <p>
-                            {this.state.loading_status==='loading' ?
-                                <button disabled="disbled">
-                                    <span className="icon icon-loading" />
-                                    &nbsp;正在登录
-                                </button> :
-                                <button type="submit">
-                                    <span className="icon icon-login" />
-                                    &nbsp;登录
-                                </button>
-                            }
-                            <button type="button" onClick={()=>{token.set_value(null);}}>退出</button>
-                        </p>
-                        <p>
-                            您的密码会被发送到 PKU Helper 服务器 <br />
-                            我们不会记录您的密码和个人信息
-                        </p>
-                    </form>
+                            </p>
+                        </div> :
+                        <p>登录后可以使用关注、回复等功能</p>
+                    }
+                    <p>
+                        <label>
+                            　学号&nbsp;
+                            <input ref={this.username_ref} type="tel" />
+                        </label>
+                        <button type="button" disabled={this.state.loading_status==='loading'}
+                                onClick={(e)=>this.do_sendcode()}>
+                            发送验证码
+                        </button>
+                    </p>
+                    <p>
+                        <label>
+                            验证码&nbsp;
+                            <input ref={this.password_ref} type="tel" />
+                        </label>
+                        <button type="button" disabled={this.state.loading_status==='loading'}
+                                onClick={(e)=>this.do_login(token.set_value)}>
+                            登录
+                        </button>
+                    </p>
+                    <p>
+                        登录请求会被发送到北大统一验证接口和 PKU Helper 服务器 <br />
+                        我们不会记录或使用您的登录信息
+                    </p>
                 </div>
             }</TokenCtx.Consumer>
         )
diff --git a/src/flows_api.js b/src/flows_api.js
index 542aabc..1903dcf 100644
--- a/src/flows_api.js
+++ b/src/flows_api.js
@@ -137,5 +137,5 @@ export const API={
                 }
                 return json;
             });
-    }
+    },
 };
\ No newline at end of file