几个静态地址：
https://cdn.jsdelivr.net/npm/swagger-ui-dist@5/swagger-ui-bundle.js
https://cdn.jsdelivr.net/npm/swagger-ui-dist@5/swagger-ui.css
https://fastapi.tiangolo.com/img/favicon.png
https://cdn.jsdelivr.net/npm/redoc@next/bundles/redoc.standalone.js

自己去github 下载或者科学上网下载到本地
然后根据下面程序的目录配置下即可

import os
from fastapi import FastAPI
from fastapi.openapi.docs import (
    get_redoc_html,
    get_swagger_ui_html,
    get_swagger_ui_oauth2_redirect_html,
)
from fastapi.staticfiles import StaticFiles

# app对象
app = FastAPI(docs_url=None, redoc_url=None)


# 静态文件位置
static_dir = os.path.dirname(os.path.abspath(__file__))
app.mount("/static", StaticFiles(directory=f"{static_dir}/static"), name="static")


@app.get("/docs", include_in_schema=False)
async def custom_swagger_ui_html():
    return get_swagger_ui_html(
        openapi_url=app.openapi_url,
        title=app.title + " - Swagger UI",
        oauth2_redirect_url=app.swagger_ui_oauth2_redirect_url,
        swagger_js_url="/static/swagger-ui/swagger-ui-bundle.js",
        swagger_css_url="/static/swagger-ui/swagger-ui.css",
    )


@app.get(app.swagger_ui_oauth2_redirect_url, include_in_schema=False)
async def swagger_ui_redirect():
    return get_swagger_ui_oauth2_redirect_html()


@app.get("/redoc", include_in_schema=False)
async def redoc_html():
    return get_redoc_html(
        openapi_url=app.openapi_url,
        title=app.title + " - ReDoc",
        redoc_js_url="/static/redoc/redoc.standalone.js",
    )


@app.get("/")
def read_root():
    return {"Hello": "World"}


if __name__ == '__main__':
    import uvicorn
    uvicorn.run(app, host="127.0.0.1", port=8000)