diff --git a/go/pikapi/config/common.go b/go/pikapi/config/common.go
index 2c8d1f1..7e46166 100644
--- a/go/pikapi/config/common.go
+++ b/go/pikapi/config/common.go
@@ -9,7 +9,7 @@ import (
 	"pgo/pikapi/utils"
 )
 
-// InitApplication 初始化文件保存的位置
+// InitApplication 由不同的平台直接调用, 根据提供的路径初始化数据库, 资料文件夹
 func InitApplication(applicationDir string) {
 	println("初始化 : " + applicationDir)
 	var databasesDir, remoteDir, downloadDir, tmpDir string
diff --git a/go/pikapi/controller/client.go b/go/pikapi/controller/client.go
index 2ad40e1..326db00 100644
--- a/go/pikapi/controller/client.go
+++ b/go/pikapi/controller/client.go
@@ -1,7 +1,8 @@
+// 透传Client的功能并增加缓存
+
 package controller
 
 import (
-	"context"
 	"encoding/json"
 	"fmt"
 	source "github.com/niuhuan/pica-go"
@@ -12,9 +13,13 @@ import (
 	"pgo/pikapi/database/network_cache"
 	"pgo/pikapi/database/properties"
 	"regexp"
+	"time"
+)
+
+import (
+	"context"
 	"strconv"
 	"strings"
-	"time"
 )
 
 func InitClient() {
@@ -405,7 +410,7 @@ func postComment(params string) (string, error) {
 
 func postChildComment(params string) (string, error) {
 	var paramsStruct struct {
-		ComicId string `json:"comicId"`
+		ComicId   string `json:"comicId"`
 		CommentId string `json:"commentId"`
 		Content   string `json:"content"`
 	}
diff --git a/go/pikapi/controller/common.go b/go/pikapi/controller/common.go
index 932c5a6..b3c7d1f 100644
--- a/go/pikapi/controller/common.go
+++ b/go/pikapi/controller/common.go
@@ -36,6 +36,7 @@ func notifyExport(str string) {
 	onEvent("EXPORT", str)
 }
 
+// 将interface序列化成字符串, 方便与flutter通信
 func serialize(point interface{}, err error) (string, error) {
 	if err != nil {
 		return "", err
diff --git a/go/pikapi/controller/download.go b/go/pikapi/controller/download.go
index feb6e54..000b263 100644
--- a/go/pikapi/controller/download.go
+++ b/go/pikapi/controller/download.go
@@ -11,6 +11,10 @@ import (
 	"time"
 )
 
+// 使用协程进行后台下载
+// downloadRunning 如果为false则停止下载
+// downloadRestart 为true则取消从新启动下载功能
+
 var downloadRunning = false
 var downloadRestart = false
 
@@ -18,16 +22,24 @@ var downloadingComic *comic_center.ComicDownload
 var downloadingEp *comic_center.ComicDownloadEp
 var downloadingPicture *comic_center.ComicDownloadPicture
 
+var dlFlag = true
+
+// 程序启动后仅调用一次, 启动后台线程
 func downloadBackground() {
 	println("后台线程启动")
-	go downloadBegin()
+	if dlFlag {
+		dlFlag = false
+		go downloadBegin()
+	}
 }
 
+// 下载启动/重新启动会暂停三秒
 func downloadBegin() {
 	time.Sleep(time.Second * 3)
 	go downloadLoadComic()
 }
 
+// 下载周期中, 每个下载单元会调用此方法, 如果返回true应该停止当前动作
 func downloadHasStop() bool {
 	if !downloadRunning {
 		go downloadBegin()
@@ -41,6 +53,7 @@ func downloadHasStop() bool {
 	return false
 }
 
+// 删除下载任务, 当用户要删除下载的时候, 他会被加入删除队列, 而不是直接被删除, 以减少出错
 func downloadDelete() bool {
 	c, e := comic_center.DeletingComic()
 	if e != nil {
@@ -57,39 +70,50 @@ func downloadDelete() bool {
 	return false
 }
 
+// 加载第一个需要下载的漫画
 func downloadLoadComic() {
+	// 每次下载完一个漫画, 或者启动的时候, 首先进行删除任务
 	for downloadDelete() {
 	}
+	// 检测是否需要停止
 	if downloadHasStop() {
 		return
 	}
+	// 找到第一个要下载的漫画, 查库有错误就停止, 因为这些错误很少出现, 一旦出现必然是严重的, 例如数据库文件突然被删除
 	var err error
 	downloadingComic, err = comic_center.LoadFirstNeedDownload()
-	// 查库有错误就停止
 	if err != nil {
 		panic(err)
 	}
+	// 处理找到的下载任务
 	go downloadInitComic()
 }
 
+// 初始化找到的下载任务
 func downloadInitComic() {
+	// 检测是否需要停止
 	if downloadHasStop() {
 		return
 	}
+	// 若没有漫画要下载则重新启动
 	if downloadingComic == nil {
 		println("没有找到要下载的漫画")
 		go downloadBegin()
 		return
 	}
+	// 打印日志, 并向前端的eventChannel发送下载信息
 	println("正在下载漫画 " + downloadingComic.Title)
 	downloadComicEventSend(downloadingComic)
 	eps, err := comic_center.ListDownloadEpByComicId(downloadingComic.ID)
 	if err != nil {
 		panic(err)
 	}
+	// 找到这个漫画需要下载的EP, 并搜索获取图片地址
 	for _, ep := range eps {
+		// FetchedPictures字段标志着这个章节的图片地址有没有获取过, 如果没有获取过就重新获取
 		if !ep.FetchedPictures {
 			println("正在获取章节的图片 " + downloadingComic.Title + " " + ep.Title)
+			// 搜索图片地址, 如果五次没有请求成功, 就不在请求
 			for i := 0; i < 5; i++ {
 				if client.Token == "" {
 					continue
@@ -102,6 +126,7 @@ func downloadInitComic() {
 				ep.FetchedPictures = true
 				break
 			}
+			// 如果未能获取图片地址, 则直接置为失败
 			if !ep.FetchedPictures {
 				println("章节的图片获取失败 " + downloadingComic.Title + " " + ep.Title)
 				err = comic_center.EpFailed(ep.ID)
@@ -115,11 +140,14 @@ func downloadInitComic() {
 			}
 		}
 	}
+	// 获取图片地址结束, 去初始化下载的章节
 	go downloadLoadEp()
 }
 
+// 获取图片地址
 func downloadFetchPictures(downloadEp *comic_center.ComicDownloadEp) error {
 	var list []comic_center.ComicDownloadPicture
+	// 官方的图片只能分页获取, 从第1页开始获取, 每页最多40张图片
 	page := 1
 	for true {
 		rsp, err := client.ComicPicturePage(downloadingComic.ID, int(downloadEp.EpOrder), page)
@@ -137,12 +165,14 @@ func downloadFetchPictures(downloadEp *comic_center.ComicDownloadEp) error {
 				Path:         doc.Media.Path,
 			})
 		}
+		// 如果不是最后一页, 页码加1, 获取下一页
 		if rsp.Page.Page < rsp.Page.Pages {
 			page++
 			continue
 		}
 		break
 	}
+	// 保存获取到的图片
 	err := comic_center.FetchPictures(downloadEp.ComicId, downloadEp.ID, &list)
 	if err != nil {
 		panic(err)
@@ -151,10 +181,13 @@ func downloadFetchPictures(downloadEp *comic_center.ComicDownloadEp) error {
 	return err
 }
 
+// 初始化下载
 func downloadLoadEp() {
+	// 周期停止检测
 	if downloadHasStop() {
 		return
 	}
+	// 找到第一个需要下载的章节并去处理 （未下载失败的, 且未完成下载的）
 	var err error
 	downloadingEp, err = comic_center.LoadFirstNeedDownloadEp(downloadingComic.ID)
 	if err != nil {
@@ -163,29 +196,36 @@ func downloadLoadEp() {
 	go downloadInitEp()
 }
 
+// 处理需要下载的EP
 func downloadInitEp() {
 	if downloadingEp == nil {
 		// 所有Ep都下完了, 汇总Download下载情况
 		go downloadSummaryDownload()
 		return
 	}
+	// 没有下载完则去下载图片
 	println("正在下载章节 " + downloadingEp.Title)
 	go downloadLoadPicture()
 }
 
+// EP下载汇总
 func downloadSummaryDownload() {
+	// 暂停检测
 	if downloadHasStop() {
 		return
 	}
+	// 加载这个漫画的所有EP
 	list, err := comic_center.ListDownloadEpByComicId(downloadingComic.ID)
 	if err != nil {
 		panic(err)
 	}
+	// 判断所有章节是否下载完成
 	over := true
 	for _, downloadEp := range list {
 		over = over && downloadEp.DownloadFinished
 	}
 	if over {
+		// 如果所有章节下载完成则下载成功
 		err = comic_center.DownloadSuccess(downloadingComic.ID)
 		if err != nil {
 			panic(err)
@@ -193,17 +233,22 @@ func downloadSummaryDownload() {
 		downloadingComic.DownloadFinished = true
 		downloadingComic.DownloadFinishedTime = time.Now()
 	} else {
+		// 否则下载失败
 		err = comic_center.DownloadFailed(downloadingComic.ID)
 		if err != nil {
 			panic(err)
 		}
 		downloadingComic.DownloadFailed = true
 	}
+	// 向前端发送下载状态
 	downloadComicEventSend(downloadingComic)
+	// 去下载下一个漫画
 	go downloadLoadComic()
 }
 
+// 加载需要下载的图片
 func downloadLoadPicture() {
+	// 暂停检测
 	if downloadHasStop() {
 		return
 	}
@@ -216,6 +261,7 @@ func downloadLoadPicture() {
 }
 
 func downloadInitPicture() {
+	// 暂停检测
 	if downloadHasStop() {
 		return
 	}
@@ -224,42 +270,50 @@ func downloadInitPicture() {
 		go downloadSummaryEp()
 		return
 	}
+	// 下载图片, 最多重试5次
 	println("正在下载图片 " + fmt.Sprintf("%d", downloadingPicture.RankInEp))
 	for i := 0; i < 5; i++ {
 		err := downloadThePicture(downloadingPicture)
 		if err != nil {
 			continue
 		}
+		// 对下载的漫画临时变量热更新并通知前端
 		downloadingPicture.DownloadFinished = true
 		downloadingEp.DownloadPictureCount = downloadingEp.DownloadPictureCount + 1
 		downloadingComic.DownloadPictureCount = downloadingComic.DownloadPictureCount + 1
 		downloadComicEventSend(downloadingComic)
 		break
 	}
+	// 没能下载成功, 图片置为下载失败
 	if !downloadingPicture.DownloadFinished {
 		err := comic_center.PictureFailed(downloadingPicture.ID)
 		if err != nil {
 			panic(err)
 		}
 	}
+	// 加载下一张需要下载的图片
 	go downloadLoadPicture()
 }
 
+// 下载指定图片
 func downloadThePicture(picturePoint *comic_center.ComicDownloadPicture) error {
+	// 为了不和页面前端浏览的数据冲突, 使用url做hash锁
 	lock := utils2.HashLock(fmt.Sprintf("%s$%s", picturePoint.FileServer, picturePoint.Path))
 	lock.Lock()
 	defer lock.Unlock()
+	// 图片保存位置使用相对路径储存, 使用绝对路径操作
 	picturePath := fmt.Sprintf("%s/%d/%d", picturePoint.ComicId, picturePoint.EpOrder, picturePoint.RankInEp)
 	realPath := downloadPath(picturePath)
-	// 从缓存
+	// 从缓存获取图片
 	buff, img, format, err := decodeFromCache(picturePoint.FileServer, picturePoint.Path)
 	if err != nil {
-		// 从网络
+		// 若缓存不存在, 则从网络获取
 		buff, img, format, err = decodeFromUrl(picturePoint.FileServer, picturePoint.Path)
 	}
 	if err != nil {
 		return err
 	}
+	// 将图片保存到文件
 	dir := filepath.Dir(realPath)
 	if _, err := os.Stat(dir); os.IsNotExist(err) {
 		os.Mkdir(dir, const_value.CreateDirMode)
@@ -268,6 +322,7 @@ func downloadThePicture(picturePoint *comic_center.ComicDownloadPicture) error {
 	if err != nil {
 		return err
 	}
+	// 存入数据库
 	return comic_center.PictureSuccess(
 		picturePoint.ComicId,
 		picturePoint.EpId,
@@ -280,14 +335,18 @@ func downloadThePicture(picturePoint *comic_center.ComicDownloadPicture) error {
 	)
 }
 
+// EP 下载内容汇总
 func downloadSummaryEp() {
+	// 暂停检测
 	if downloadHasStop() {
 		return
 	}
+	// 找到所有下载的图片
 	list, err := comic_center.ListDownloadPictureByEpId(downloadingEp.ID)
 	if err != nil {
 		panic(err)
 	}
+	// 全部下载完成置为成功, 否则置为失败
 	over := true
 	for _, downloadPicture := range list {
 		over = over && downloadPicture.DownloadFinished
@@ -303,5 +362,6 @@ func downloadSummaryEp() {
 			panic(err)
 		}
 	}
+	// 去加载下一个EP
 	go downloadLoadEp()
 }
diff --git a/go/pikapi/controller/network.go b/go/pikapi/controller/network.go
index 9be445e..dc18a50 100644
--- a/go/pikapi/controller/network.go
+++ b/go/pikapi/controller/network.go
@@ -5,6 +5,7 @@ import (
 	"strings"
 )
 
+// 获取IP的集合
 func clientIpSet() (string, error) {
 	address, err := net.InterfaceAddrs()
 	if err != nil {
diff --git a/go/pikapi/controller/special.go b/go/pikapi/controller/special.go
index ed97d49..2ebbaca 100644
--- a/go/pikapi/controller/special.go
+++ b/go/pikapi/controller/special.go
@@ -2,6 +2,7 @@ package controller
 
 import "pgo/pikapi/database/comic_center"
 
+// 根据comicId，获得标题，但是必须是下载的内容(暂未使用)
 func specialDownloadTitle(comicId string) (string, error) {
 	info, err := comic_center.DownloadInfo(comicId)
 	if err != nil {
diff --git a/go/pikapi/database/comic_center/center.go b/go/pikapi/database/comic_center/center.go
index 7690d0f..7fdea84 100644
--- a/go/pikapi/database/comic_center/center.go
+++ b/go/pikapi/database/comic_center/center.go
@@ -113,6 +113,8 @@ func ViewComicUpdateInfo(view *ComicView) error {
 }
 
 func ViewComic(comicId string) error {
+	mutex.Lock()
+	defer mutex.Unlock()
 	return db.Model(&ComicView{}).Where(
 		"id = ?", comicId,
 	).Update(
diff --git a/go/pikapi/utils/time.go b/go/pikapi/utils/time.go
index 6dc3864..8b1b471 100644
--- a/go/pikapi/utils/time.go
+++ b/go/pikapi/utils/time.go
@@ -2,6 +2,7 @@ package utils
 
 import "time"
 
+// Timestamp 获取当前的Unix时间戳
 func Timestamp() int64 {
 	return time.Now().UnixNano() / int64(time.Millisecond)
 }