diff --git a/src/scripts/i18n/en-US.json b/src/scripts/i18n/en-US.json
index 302040e..614fb00 100644
--- a/src/scripts/i18n/en-US.json
+++ b/src/scripts/i18n/en-US.json
@@ -116,6 +116,7 @@
         "errorParse": "An error has occurred when parsing the OPML file.",
         "errorParseHint": "Please ensure that the file isn't corrupted and is encoded with UTF-8.",
         "errorImport": "Error importing {count, plural, =1 {# source} other {# sources}}.",
+        "exist": "This source already exists.",
         "opmlFile": "OPML File",
         "name": "Source name",
         "editName": "Edit name",
diff --git a/src/scripts/i18n/zh-CN.json b/src/scripts/i18n/zh-CN.json
index 4bc4608..2c251df 100644
--- a/src/scripts/i18n/zh-CN.json
+++ b/src/scripts/i18n/zh-CN.json
@@ -114,6 +114,7 @@
         "errorParse": "解析OPML文件时出错",
         "errorParseHint": "请确保OPML文件完整且使用UTF-8编码。",
         "errorImport": "导入{count}项订阅源时出错",
+        "exist": "该订阅源已存在",
         "opmlFile": "OPML文件",
         "name": "订阅源名称",
         "editName": "修改名称",
diff --git a/src/scripts/models/source.ts b/src/scripts/models/source.ts
index 787abc7..20f34a7 100644
--- a/src/scripts/models/source.ts
+++ b/src/scripts/models/source.ts
@@ -204,29 +204,26 @@ export function addSourceFailure(err, batch: boolean): SourceActionTypes {
     }
 }
 
-function insertSource(source: RSSSource, trials = 0): AppThunk<Promise<RSSSource>> {
-    return (dispatch, getState) => {
+let insertPromises = Promise.resolve()
+function insertSource(source: RSSSource): AppThunk<Promise<RSSSource>> {
+    return (_, getState) => {
         return new Promise((resolve, reject) => {
-            if (trials >= 25) {
-                reject("Failed to insert the source into NeDB.")
-                return
-            }
-            let sids = Object.values(getState().sources).map(s => s.sid)
-            source.sid = Math.max(...sids, -1) + 1
-            db.sdb.insert(source, (err, inserted) => {
-                if (err) {
-                    if (/^Can't insert key [0-9]+,/.test(err.message)) {
-                        console.log("sid conflict")
-                        dispatch(insertSource(source, trials + 1))
-                            .then(inserted => resolve(inserted))
-                            .catch(err => reject(err))
+            insertPromises = insertPromises.then(() => new Promise(innerResolve => {
+                let sids = Object.values(getState().sources).map(s => s.sid)
+                source.sid = Math.max(...sids, -1) + 1
+                db.sdb.insert(source, (err, inserted) => {
+                    if (err) {
+                        if ((new RegExp(`^Can't insert key ${source.url},`)).test(err.message)) {
+                            reject(intl.get("sources.exist"))
+                        } else {
+                            reject(err)
+                        }
                     } else {
-                        reject(err)
+                        resolve(inserted)
                     }
-                } else {
-                    resolve(inserted)
-                }
-            })
+                    innerResolve()
+                })
+            }))
         })
     }
 
diff --git a/src/scripts/utils.ts b/src/scripts/utils.ts
index 5618684..d352ed5 100644
--- a/src/scripts/utils.ts
+++ b/src/scripts/utils.ts
@@ -47,7 +47,7 @@ export async function parseRSS(url: string) {
             throw new Error(intl.get("log.parseError"))
         }
     } else {
-        throw new Error(result.statusText)
+        throw new Error(result.status + " " + result.statusText)
     }
 }