diff --git a/src/config.ts b/src/config.ts
index 40aaf0c..e851ae8 100644
--- a/src/config.ts
+++ b/src/config.ts
@@ -235,6 +235,7 @@ export interface Config extends PromptConfig, ParamConfig {
   requestTimeout?: number
   recallTimeout?: number
   maxConcurrency?: number
+  globalConcurrency?: number
   pollInterval?: number
   trustedWorkers?: boolean
   workflowText2Image?: string
@@ -413,6 +414,7 @@ export const Config = Schema.intersect([
     requestTimeout: Schema.number().role('time').description('当请求超过这个时间时会中止并提示超时。').default(Time.minute),
     recallTimeout: Schema.number().role('time').description('图片发送后自动撤回的时间 (设置为 0 以禁用此功能)。').default(0),
     maxConcurrency: Schema.number().description('单个频道下的最大并发数量 (设置为 0 以禁用此功能)。').default(0),
+    globalConcurrency: Schema.number().min(0).description('全局的最大并发数量 (设置为 0 以禁用此功能)。').default(0),
   }).description('高级设置'),
 ]) as Schema<Config>
 
diff --git a/src/index.ts b/src/index.ts
index 101f0ac..74cbacf 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,4 +1,4 @@
-import { Computed, Context, Dict, h, Logger, omit, Quester, Session, SessionError, trimSlash } from 'koishi'
+import { Computed, Context, Dict, h, Logger, omit, Quester, Session, SessionError, sleep, trimSlash } from 'koishi'
 import { Config, modelMap, models, orientMap, parseInput, sampler, upscalers, scheduler } from './config'
 import { ImageData, StableDiffusionWebUI } from './types'
 import { closestMultiple, download, forceDataPrefix, getImageSize, login, NetworkError, project, resizeInput, Size } from './utils'
@@ -10,6 +10,12 @@ import { readFile } from 'fs/promises'
 
 export * from './config'
 
+declare module 'koishi' {
+  interface Events {
+    'novelai/finish'(id: string): void
+  }
+}
+
 export const reactive = true
 export const name = 'novelai'
 
@@ -45,6 +51,7 @@ export function apply(ctx: Context, config: Config) {
 
   const tasks: Dict<Set<string>> = Object.create(null)
   const globalTasks = new Set<string>()
+  const globalPending = new Set<string>()
 
   let tokenTask: Promise<string> = null
   const getToken = () => tokenTask ||= login(ctx)
@@ -298,10 +305,29 @@ export function apply(ctx: Context, config: Config) {
         ? session.text('.pending', [globalTasks.size])
         : session.text('.waiting'))
 
+      if (config.globalConcurrency) {
+        if (globalTasks.size >= config.globalConcurrency) {
+          const pendingId = container.pop()
+          globalPending.add(pendingId)
+          await new Promise<void>((resolve) => {
+            const dispose = ctx.on('novelai/finish', (id) => {
+              if (id !== pendingId) return
+              resolve()
+              dispose()
+            }
+          }))
+        }
+      }
+
       container.forEach((id) => globalTasks.add(id))
       const cleanUp = (id: string) => {
         tasks[session.cid]?.delete(id)
         globalTasks.delete(id)
+        if (globalPending.size) {
+          const id = globalPending.values().next().value
+          globalPending.delete(id)
+          ctx.parallel('novelai/finish', id)
+        }
       }
 
       const path = (() => {
@@ -418,8 +444,8 @@ export function apply(ctx: Context, config: Config) {
               const body = new FormData()
               const capture = /^data:([\w/.+-]+);base64,(.*)$/.exec(image.dataUrl)
               const [, mime,] = capture
-              
-              let name = Date.now().toString() 
+
+              let name = Date.now().toString()
               const ext = mime === 'image/jpeg' ? 'jpg' : mime === 'image/png' ? 'png' : ''
               if (ext) name += `.${ext}`
               const imageFile = new Blob([image.buffer], {type:mime})
@@ -435,7 +461,7 @@ export function apply(ctx: Context, config: Config) {
                 const data = res.data
                 let imagePath = data.name
                 if (data.subfolder) imagePath = data.subfolder + '/' + imagePath
-      
+
                 for (const nodeId in prompt) {
                   if (prompt[nodeId].class_type === 'LoadImage') {
                     prompt[nodeId].inputs.image = imagePath
@@ -460,7 +486,7 @@ export function apply(ctx: Context, config: Config) {
                 const negativeeNodeId = prompt[nodeId].inputs.negative[0]
                 const latentImageNodeId = prompt[nodeId].inputs.latent_image[0]
                 prompt[positiveNodeId].inputs.text = parameters.prompt
-                prompt[negativeeNodeId].inputs.text = parameters.uc    
+                prompt[negativeeNodeId].inputs.text = parameters.uc
                 prompt[latentImageNodeId].inputs.width = parameters.width
                 prompt[latentImageNodeId].inputs.height = parameters.height
                 prompt[latentImageNodeId].inputs.batch_size = parameters.n_samples
@@ -522,7 +548,6 @@ export function apply(ctx: Context, config: Config) {
             const uuid = res.data.id
 
             const check = () => ctx.http.get(trimSlash(config.endpoint) + '/api/v2/generate/check/' + uuid).then((res) => res.done)
-            const sleep = (ms: number) => new Promise((resolve) => setTimeout(resolve, ms))
             while (await check() === false) {
               await sleep(config.pollInterval)
             }