极简方法：
下载you-get库，知道视频地址就ok，要是安装并配置ffmpeg会直接将下载好的音频和视频合并，方法如下：
`#在cmd中输入
you-get -o 保存地址 url地址
`
完整代码 --2025.8.12，其中用到了moviepy(ffmpeg)视频合并功能，因为B站视频的音频和视频是分开的
点击查看代码
from moviepy.editor import AudioFileClip, VideoFileClip, CompositeVideoClip
import tempfile
import os
import requests
import re
import json
# 配置区
url = 'https://www.bilibili.com/video/BV18gGezoELy?t=2.5'
cookie = "你自己的cookie"
headers = {"Referer": url,"User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36...","Cookie": cookie
}
try:# 请求与解析response = requests.get(url=url, headers=headers, timeout=10)response.raise_for_status()html = response.texttitle = re.findall('title="(.*?)"', html)[0]print(f"视频标题: {title}")info = re.findall('window.__playinfo__=(.*?)</script>', html)[0]json_data = json.loads(info)video_url = json_data['data']['dash']['video'][0]['baseUrl']audio_url = json_data['data']['dash']['audio'][0]['baseUrl']print(f"视频流: {video_url[:50]}...")print(f"音频流: {audio_url[:50]}...")# 下载媒体video_content = requests.get(video_url, headers=headers).contentaudio_content = requests.get(audio_url, headers=headers).content# 临时文件处理with tempfile.NamedTemporaryFile(mode="wb", delete=False, suffix=".mp4") as video_temp:video_temp.write(video_content)video_temp_path = video_temp.namewith tempfile.NamedTemporaryFile(mode="wb", delete=False, suffix=".mp3") as audio_temp:audio_temp.write(audio_content)audio_temp_path = audio_temp.name # 修正路径# 音视频合成video = VideoFileClip(video_temp_path)audio = AudioFileClip(audio_temp_path)final_video = video.set_audio(audio) # 更简洁的合成方式# 最终视频输出部分（修复后）output_dir = "../shipin"os.makedirs(output_dir, exist_ok=True)final_video.write_videofile(f"{output_dir}/{title}.mp4",codec="libx264",audio_codec="aac",logger='bar' # 或完全移除 progress_bar 参数)
finally:# 资源清理if 'video' in locals(): video.close()if 'audio' in locals(): audio.close()if os.path.exists(video_temp_path): os.remove(video_temp_path)if os.path.exists(audio_temp_path): os.remove(audio_temp_path)print("临时文件已清理")