diff --git a/packages/fps-importer/handler.ts b/packages/fps-importer/handler.ts
index 848d578f6..e948560e2 100644
--- a/packages/fps-importer/handler.ts
+++ b/packages/fps-importer/handler.ts
@@ -5,7 +5,6 @@ import fs from 'fs-extra';
 import AdmZip from 'adm-zip';
 import xml2js from 'xml2js';
 import { LocalProblemConfig } from 'hydrooj';
-import { convertHTML } from '@hydrooj/html2md';
 import {
     Route, Handler, param, Types,
 } from 'hydrooj/dist/service/server';
@@ -26,19 +25,19 @@ class FpsProblemImportHandler extends Handler {
             if (p.description) {
                 content.push(
                     this.translate('problem.import.problem_description'),
-                    p.description.map(convertHTML).join('\n'),
+                    p.description.join('\n'),
                 );
             }
             if (p.input) {
                 content.push(
                     this.translate('problem.import.input_format'),
-                    p.input.map(convertHTML).join('\n'),
+                    p.input.join('\n'),
                 );
             }
             if (p.output) {
                 content.push(
                     this.translate('problem.import.output_format'),
-                    p.output.map(convertHTML).join('\n'),
+                    p.output.join('\n'),
                 );
             }
             if (p.sample_input) {
@@ -58,7 +57,7 @@ class FpsProblemImportHandler extends Handler {
             if (p.hint) {
                 content.push(
                     this.translate('problem.import.hint'),
-                    p.hint.map(convertHTML).join('\n'),
+                    p.hint.join('\n'),
                 );
             }
             const config: LocalProblemConfig = {
@@ -79,6 +78,7 @@ class FpsProblemImportHandler extends Handler {
                 });
             });
             await problem.setTestdata(domainId, pid, file);
+            await problem.edit(domainId, pid, { html: true });
             await fs.unlink(file);
         }
         this.response.body = { count: result.fps.item.length };
diff --git a/packages/fps-importer/package.json b/packages/fps-importer/package.json
index 469253930..9aa0753e7 100644
--- a/packages/fps-importer/package.json
+++ b/packages/fps-importer/package.json
@@ -1,13 +1,12 @@
 {
     "name": "@hydrooj/fps-importer",
-    "version": "1.0.2",
+    "version": "1.0.3",
     "description": "Import FPS problems",
     "main": "package.json",
     "repository": "https://github.com/hydro-dev/Hydro.git",
     "author": "undefined <masnn0@outlook.com>",
     "license": "AGPL-3.0-only",
     "dependencies": {
-        "@hydrooj/html2md": "^1.0.0",
         "adm-zip": "^0.4.16",
         "fs-extra": "^9.0.1",
         "hydrooj": "^2.12.22",
diff --git a/packages/html2md/lib.ts b/packages/html2md/lib.ts
index ed0c82e00..5d8e6807c 100644
--- a/packages/html2md/lib.ts
+++ b/packages/html2md/lib.ts
@@ -2,14 +2,20 @@ import 'hydrooj';
 import TurndownService from 'turndown';
 import { JSDOM } from 'jsdom';
 
-const turndownService = new TurndownService();
+const turndownService = new TurndownService({
+    headingStyle: 'atx',
+    codeBlockStyle: 'fenced',
+    bulletListMarker: '-',
+});
 
 export function convertHTML(html: string) {
     const DOM = new JSDOM(html);
     const eles = DOM.window.document.querySelectorAll('span.katex-mathml');
     eles.forEach((ele) => {
-        const MathML = ele.innerHTML;
-        ele.parentElement.replaceWith(MathML);
+        const MathML = ele.innerHTML
+            .replace(/\\{/gmi, '{')
+            .replace(/\\}/gmi, '}');
+        ele.parentElement.replaceWith(`$${MathML}$`);
     });
     return turndownService.turndown(DOM.serialize());
 }
diff --git a/packages/html2md/package.json b/packages/html2md/package.json
index be8e0f3f8..a78fecdc9 100644
--- a/packages/html2md/package.json
+++ b/packages/html2md/package.json
@@ -2,7 +2,8 @@
     "name": "@hydrooj/html2md",
     "version": "1.0.0",
     "description": "turn html into markdown",
-    "main": "package.json",
+    "main": "lib.js",
+    "typings": "lib.d.ts",
     "repository": "https://github.com/hydro-dev/Hydro.git",
     "author": "undefined <masnn0@outlook.com>",
     "license": "AGPL-3.0-only",
@@ -19,4 +20,4 @@
         "build": "tsc",
         "lint": "eslint . --ext ts --fix"
     }
-}
+}
\ No newline at end of file
diff --git a/packages/html2md/test/lib.spec.ts b/packages/html2md/test/lib.spec.ts
new file mode 100644
index 000000000..59c9aa8fb
--- /dev/null
+++ b/packages/html2md/test/lib.spec.ts
@@ -0,0 +1,44 @@
+import 'hydrooj';
+import { convertHTML } from '@hydrooj/html2md/lib';
+
+describe('html2md', () => {
+    const Katex1 = `\
+<span class="katex">
+    <span class="katex-mathml">nn</span>
+    <span class="katex-html">
+        <span class="strut"></span>
+        <span class="strut bottom" style="vertical-align:0em;"></span>
+        <span class="base textstyle uncramped">
+            <span class="mord mathit">n</span>
+        </span>
+    </span>
+</span>`;
+    const Katex2 = `\
+<span class="katex">
+    <span class="katex-mathml">E={1,2,..,n}E=\\{1,2,..,n\\}</span>
+    <span class="katex-html">
+        <span class="strut"></span>
+        <span class="strut bottom" style="vertical-align:-0.25em;"></span>
+        <span class="base textstyle uncramped">
+            <span class="mord mathit">E</span>
+            <span class="mrel">=</span>
+            <span class="mopen">{</span>
+            <span class="mord mathrm">1</span>
+            <span class="mpunct">,</span>
+            <span class="mord mathrm">2</span>
+            <span class="mpunct">,</span>
+            <span class="mord mathrm">.</span>
+            <span class="mord mathrm">.</span>
+            <span class="mpunct">,</span>
+            <span class="mord mathit">n</span>
+            <span class="mclose">}</span>
+        </span>
+    </span>
+</span>`;
+
+    test('convertHTML', () => {
+        expect(convertHTML('<h1>Test</h1><p>test</p>')).toStrictEqual('# Test\n\ntest');
+        expect(convertHTML(Katex1)).toStrictEqual('$n$');
+        expect(convertHTML(Katex2)).toStrictEqual('$E={1,2,..,n}$');
+    });
+});
diff --git a/packages/hydrooj/package.json b/packages/hydrooj/package.json
index 1e32f53d0..684aca2c6 100644
--- a/packages/hydrooj/package.json
+++ b/packages/hydrooj/package.json
@@ -1,6 +1,6 @@
 {
     "name": "hydrooj",
-    "version": "2.12.23",
+    "version": "2.12.24",
     "bin": "bin/hydrooj.js",
     "main": "dist/loader.js",
     "typings": "dist/loader.d.ts",
diff --git a/packages/hydrooj/src/handler/problem.ts b/packages/hydrooj/src/handler/problem.ts
index a00dd5f60..7763b7291 100644
--- a/packages/hydrooj/src/handler/problem.ts
+++ b/packages/hydrooj/src/handler/problem.ts
@@ -1,5 +1,5 @@
 import { isSafeInteger, flatten } from 'lodash';
-import yaml from 'js-yaml';
+import yaml, { safeLoad } from 'js-yaml';
 import { ObjectID } from 'mongodb';
 import {
     NoProblemError, ProblemDataNotFoundError, BadRequestError,
@@ -360,7 +360,7 @@ class ProblemSettingsHandler extends ProblemManageHandler {
     async postConfig(domainId: string, pid: string | number, cfg: string) {
         const pdoc = await problem.get(domainId, pid);
         // TODO validate
-        const config = yaml.safeLoad(cfg);
+        const config = yaml.safeLoad(cfg) as any;
         await problem.edit(domainId, pdoc.docId, { config });
         this.back();
     }
diff --git a/packages/hydrooj/src/interface.ts b/packages/hydrooj/src/interface.ts
index 3d48274ff..35661ce55 100644
--- a/packages/hydrooj/src/interface.ts
+++ b/packages/hydrooj/src/interface.ts
@@ -141,11 +141,12 @@ export interface Pdoc {
     hidden: boolean,
     config: ProblemConfig,
     acMsg?: string,
+    html?: boolean,
 
     difficulty?: number,
     difficultyAlgo?: number,
     difficultyAdmin?: number,
-    difficultySetting?: number,
+    difficultySetting?: any,
 }
 
 export type Pdict = NumericDictionary<Pdoc>;
diff --git a/packages/hydrooj/src/model/problem.ts b/packages/hydrooj/src/model/problem.ts
index 77fcbb04a..f8e2c9fa0 100644
--- a/packages/hydrooj/src/model/problem.ts
+++ b/packages/hydrooj/src/model/problem.ts
@@ -1,5 +1,6 @@
-import { ObjectID } from 'mongodb';
+import { ObjectID, FilterQuery } from 'mongodb';
 import { Dictionary } from 'lodash';
+import { safeLoad } from 'js-yaml';
 import { STATUS } from './builtin';
 import * as file from './file';
 import * as document from './document';
@@ -29,6 +30,7 @@ export const pdocHidden: Pdoc = {
     owner: 1,
     title: '*',
     content: '',
+    html: false,
     nSubmit: 0,
     nAccept: 0,
     difficulty: 0,
@@ -75,11 +77,11 @@ export function getMulti(domainId: string, query: object) {
     return document.getMulti(domainId, document.TYPE_PROBLEM, query);
 }
 
-export function getMultiStatus(domainId: string, query: object) {
+export function getMultiStatus(domainId: string, query: FilterQuery<Pdoc>) {
     return document.getMultiStatus(domainId, document.TYPE_PROBLEM, query);
 }
 
-export function edit(domainId: string, _id: number, $set: any): Promise<Pdoc> {
+export function edit(domainId: string, _id: number, $set: Partial<Pdoc>): Promise<Pdoc> {
     return document.set(domainId, document.TYPE_PROBLEM, _id, $set);
 }
 
@@ -158,7 +160,7 @@ export async function setTestdata(domainId: string, _id: number, filePath: strin
     const config = await testdataConfig.readConfig(filePath);
     const id = await file.add(filePath, 'data.zip', 1);
     if (pdoc.data instanceof ObjectID) file.del(pdoc.data);
-    return await edit(domainId, _id, { data: id, config });
+    return await edit(domainId, _id, { data: id, config: safeLoad(config) as any });
 }
 
 global.Hydro.model.problem = {