原来是jupyter本身已经有loop了的原因。

这个在pycharm 命令窗口都可以运行。但是在vscode就不行了。

import asyncio
from threading import Thread


def run_async(awaitable, *args, loop=None, **kwargs):
    policy = asyncio.get_event_loop_policy()
    policy._loop_factory = asyncio.SelectorEventLoop

    if loop is None:
        loop = asyncio.new_event_loop()
    task = loop.create_task(awaitable(*args, **kwargs))
    loop.run_until_complete(task)
    return task.result()


def run():
    loop = asyncio.new_event_loop()
    return run_async(_run, loop=loop)

async def _run():
    print ("_run")
    await asyncio.sleep(0.1)



if __name__ == '__main__': 
    run()

在VSCode试了下可以正常运行啊，看看是不是你的VSCode默认的Python环境配置错了