diff --git a/public/react/public/js/jsFromMiddleLayer/base64.js b/public/react/public/js/jsFromMiddleLayer/base64.js
new file mode 100644
index 000000000..4494a50e3
--- /dev/null
+++ b/public/react/public/js/jsFromMiddleLayer/base64.js
@@ -0,0 +1,103 @@
+function Base64() {
+
+	// private property
+	_keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
+
+	// public method for encoding
+	this.encode = function (input) {
+		var output = "";
+		var chr1, chr2, chr3, enc1, enc2, enc3, enc4;
+		var i = 0;
+		input = _utf8_encode(input);
+		while (i < input.length) {
+			chr1 = input.charCodeAt(i++);
+			chr2 = input.charCodeAt(i++);
+			chr3 = input.charCodeAt(i++);
+			enc1 = chr1 >> 2;
+			enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
+			enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
+			enc4 = chr3 & 63;
+			if (isNaN(chr2)) {
+				enc3 = enc4 = 64;
+			} else if (isNaN(chr3)) {
+				enc4 = 64;
+			}
+			output = output +
+				_keyStr.charAt(enc1) + _keyStr.charAt(enc2) +
+				_keyStr.charAt(enc3) + _keyStr.charAt(enc4);
+		}
+		return output;
+	}
+
+	// public method for decoding
+	this.decode = function (input) {
+		var output = "";
+		var chr1, chr2, chr3;
+		var enc1, enc2, enc3, enc4;
+		var i = 0;
+		input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");
+		while (i < input.length) {
+			enc1 = _keyStr.indexOf(input.charAt(i++));
+			enc2 = _keyStr.indexOf(input.charAt(i++));
+			enc3 = _keyStr.indexOf(input.charAt(i++));
+			enc4 = _keyStr.indexOf(input.charAt(i++));
+			chr1 = (enc1 << 2) | (enc2 >> 4);
+			chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
+			chr3 = ((enc3 & 3) << 6) | enc4;
+			output = output + String.fromCharCode(chr1);
+			if (enc3 != 64) {
+				output = output + String.fromCharCode(chr2);
+			}
+			if (enc4 != 64) {
+				output = output + String.fromCharCode(chr3);
+			}
+		}
+		output = _utf8_decode(output);
+		return output;
+	}
+
+	// private method for UTF-8 encoding
+	_utf8_encode = function (string) {
+		string = string.replace(/\r\n/g,"\n");
+		var utftext = "";
+		for (var n = 0; n < string.length; n++) {
+			var c = string.charCodeAt(n);
+			if (c < 128) {
+				utftext += String.fromCharCode(c);
+			} else if((c > 127) && (c < 2048)) {
+				utftext += String.fromCharCode((c >> 6) | 192);
+				utftext += String.fromCharCode((c & 63) | 128);
+			} else {
+				utftext += String.fromCharCode((c >> 12) | 224);
+				utftext += String.fromCharCode(((c >> 6) & 63) | 128);
+				utftext += String.fromCharCode((c & 63) | 128);
+			}
+
+		}
+		return utftext;
+	}
+
+	// private method for UTF-8 decoding
+	_utf8_decode = function (utftext) {
+		var string = "";
+		var i = 0;
+		var c = c1 = c2 = 0;
+		while ( i < utftext.length ) {
+			c = utftext.charCodeAt(i);
+			if (c < 128) {
+				string += String.fromCharCode(c);
+				i++;
+			} else if((c > 191) && (c < 224)) {
+				c2 = utftext.charCodeAt(i+1);
+				string += String.fromCharCode(((c & 31) << 6) | (c2 & 63));
+				i += 2;
+			} else {
+				c2 = utftext.charCodeAt(i+1);
+				c3 = utftext.charCodeAt(i+2);
+				string += String.fromCharCode(((c & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63));
+				i += 3;
+			}
+		}
+		return string;
+	}
+}
\ No newline at end of file
diff --git a/public/react/src/modules/courses/Resource/Fileslistitem.js b/public/react/src/modules/courses/Resource/Fileslistitem.js
index 8a8ff674c..c3998700f 100644
--- a/public/react/src/modules/courses/Resource/Fileslistitem.js
+++ b/public/react/src/modules/courses/Resource/Fileslistitem.js
@@ -6,7 +6,6 @@ import {getImageUrl} from 'educoder';
 import axios from 'axios'
 import {getUrl} from 'educoder';
 import moment from 'moment'
-import { Base64 } from 'js-base64';
 import CoursesListType from '../coursesPublic/CoursesListType';
 import Showoldfiles from "../coursesPublic/Showoldfiles";
 import Modals from '../../modals/Modals';
diff --git a/public/react/src/modules/courses/shixunHomework/ShixunStudentWork.js b/public/react/src/modules/courses/shixunHomework/ShixunStudentWork.js
index 90bc23d99..879f90cc7 100644
--- a/public/react/src/modules/courses/shixunHomework/ShixunStudentWork.js
+++ b/public/react/src/modules/courses/shixunHomework/ShixunStudentWork.js
@@ -33,7 +33,6 @@ import '../css/Courses.css'
 import './style.css'
 import moment from 'moment';
 import 'moment/locale/zh-cn';
-import {Base64} from 'js-base64';
 
 const Search = Input.Search;
 const CheckboxGroup = Checkbox.Group;
diff --git a/public/react/src/modules/courses/shixunHomework/ShixunWorkReport.js b/public/react/src/modules/courses/shixunHomework/ShixunWorkReport.js
index fc34e0667..9a331cdef 100644
--- a/public/react/src/modules/courses/shixunHomework/ShixunWorkReport.js
+++ b/public/react/src/modules/courses/shixunHomework/ShixunWorkReport.js
@@ -20,7 +20,6 @@ import '../css/Courses.css';
 import './style.css';
 import moment from 'moment';
 import 'moment/locale/zh-cn';
-import {Base64} from 'js-base64';
 
 class ShixunWorkReport extends Component {
 
diff --git a/public/react/src/modules/courses/shixunHomework/Trainingjobsetting.js b/public/react/src/modules/courses/shixunHomework/Trainingjobsetting.js
index 51b491861..06c4dfba2 100644
--- a/public/react/src/modules/courses/shixunHomework/Trainingjobsetting.js
+++ b/public/react/src/modules/courses/shixunHomework/Trainingjobsetting.js
@@ -4,7 +4,6 @@ import HomeworkModal from "../coursesPublic/HomeworkModal";
 import {WordsBtn, ActionBtn, handleDateString} from 'educoder';
 import PollDetailTabForthRules from '../poll/PollDetailTabForthRules';
 import ShixunWorkModal from './Shixunworkdetails/ShixunWorkModal';
-import {Base64} from 'js-base64';
 import {
     Button,
     Checkbox,
diff --git a/public/react/src/modules/courses/shixunHomework/Workquestionandanswer.js b/public/react/src/modules/courses/shixunHomework/Workquestionandanswer.js
index 170051ca6..c08024867 100644
--- a/public/react/src/modules/courses/shixunHomework/Workquestionandanswer.js
+++ b/public/react/src/modules/courses/shixunHomework/Workquestionandanswer.js
@@ -23,7 +23,6 @@ import {
 import {Link, Switch, Route, Redirect} from 'react-router-dom';
 import moment from 'moment';
 import 'moment/locale/zh-cn';
-import {Base64} from 'js-base64';
 import axios from 'axios';
 import '../css/members.css'
 import "../common/formCommon.css"