原因是国内镜像站全寄了，你设国内源没用!，换成官方的然后懂？
sudo vim /etc/apt/sources.list添加debian官方源
deb https://deb.debian.org/debian/ bullseye main contrib non-free
deb-src https://deb.debian.org/debian/ bullseye main contrib non-free
deb https://deb.debian.org/debian/ bullseye-updates main contrib non-free
deb-src https://deb.debian.org/debian/ bullseye-updates main contrib non-free
deb https://deb.debian.org/debian/ bullseye-backports main contrib non-free
deb-src https://deb.debian.org/debian/ bullseye-backports main contrib non-free
deb https://deb.debian.org/debian-security/ bullseye-security main contrib non-free
deb-src https://deb.debian.org/debian-security/ bullseye-security main contrib non-free美国源
deb http://ftp.us.debian.org/debian/ bullseye main contrib non-free
deb-src http://ftp.us.debian.org/debian/ bullseye main contrib non-free
deb http://ftp.us.debian.org/debian/ bullseye-updates main contrib non-free
deb-src http://ftp.us.debian.org/debian/ bullseye-updates main contrib non-free
deb http://ftp.us.debian.org/debian/ bullseye-backports main contrib non-free
deb-src http://ftp.us.debian.org/debian/ bullseye-backports main contrib non-free
deb http://ftp.us.debian.org/debian/ bullseye-security main contrib non-free
deb-src http://ftp.us.debian.org/debian/ bullseye-security main contrib non-free俄罗斯源
deb http://ftp.ru.debian.org/debian/ bullseye main contrib non-free
deb-src http://ftp.ru.debian.org/debian/ bullseye main contrib non-free
deb http://ftp.ru.debian.org/debian/ bullseye-updates main contrib non-free
deb-src http://ftp.ru.debian.org/debian/ bullseye-updates main contrib non-free
deb http://ftp.ru.debian.org/debian/ bullseye-backports main contrib non-free
deb-src http://ftp.ru.debian.org/debian/ bullseye-backports main contrib non-free
deb http://ftp.ru.debian.org/debian/ bullseye-security main contrib non-free
deb-src http://ftp.ru.debian.org/debian/ bullseye-security main contrib non-free小日本的源（install 成功的那一刻不小！）
deb https://ftp.jp.debian.org/debian/ bullseye main contrib non-free
deb-src https://ftp.jp.debian.org/debian/ bullseye main contrib non-free
deb https://ftp.jp.debian.org/debian/ bullseye-updates main contrib non-free
deb-src https://ftp.jp.debian.org/debian/ bullseye-updates main contrib non-free
deb https://ftp.jp.debian.org/debian/ bullseye-backports main contrib non-free
deb-src https://ftp.jp.debian.org/debian/ bullseye-backports main contrib non-free
deb https://ftp.jp.debian.org/debian/ bullseye-security main contrib non-free
deb-src https://ftp.jp.debian.org/debian/ bullseye-security main contrib non-free法国源
deb http://ftp.fr.debian.org/debian/ bullseye main contrib non-free
deb-src http://ftp.fr.debian.org/debian/ bullseye main contrib non-free
deb http://ftp.fr.debian.org/debian/ bullseye-updates main contrib non-free
deb-src http://ftp.fr.debian.org/debian/ bullseye-updates main contrib non-free
deb http://ftp.fr.debian.org/debian/ bullseye-backports main contrib non-free
deb-src http://ftp.fr.debian.org/debian/ bullseye-backports main contrib non-free
deb http://ftp.fr.debian.org/debian/ bullseye-security main contrib non-free
deb-src http://ftp.fr.debian.org/debian/ bullseye-security main contrib non-free德国源
deb http://ftp2.de.debian.org/debian/ bullseye main contrib non-free
deb-src http://ftp2.de.debian.org/debian/ bullseye main contrib non-free
deb http://ftp2.de.debian.org/debian/ bullseye-updates main contrib non-free
deb-src http://ftp2.de.debian.org/debian/ bullseye-updates main contrib non-free
deb http://ftp2.de.debian.org/debian/ bullseye-backports main contrib non-free
deb-src http://ftp2.de.debian.org/debian/ bullseye-backports main contrib non-free
deb http://ftp2.de.debian.org/debian/ bullseye-security main contrib non-free
deb-src http://ftp2.de.debian.org/debian/ bullseye-security main contrib non-free更新
sudo apt update && sudo apt upgrade只需要把网址替换一下就可以了
debian其他国家镜像站