[English included]求助，写了个群发信息的功能，用多线程后非常慢，疑似是bot.send_group_msg会在多线程中卡住

[WJZ-P]

async def group_send(group_list,msg):
ban_group=[1234]
for id in group_list:
if(id["group_id"] not in ban_group):
await bot.send_group_msg(group_id=id["group_id"],message=msg)
print(msg)
sleep(2)

#_________________________________________________________
#_________________________________________________________

@bot.on_message('private')
async def _(event: Event):

if(event.message.startswith("群发") and event.user_id==1369727119):
    msg=event.message[3:]
    try:
        group_list=await bot.get_group_list()
        threading.Thread(target=lambda:asyncio.run(group_send(group_list,msg))).start()
    except Exception as error:
        print(error)

如题，如果不使用多线程的话会正常工作，像这样就不行了，实际上不是完全卡死，而是每次消息发送间隔起码一分钟。
I wrote the codes above, I fond that when I use multithreading it can still send messages but the interval of every message is longer than 1 minutes though I set "sleep(2)"(still didn't work when I delete sleep). Could anyone help?