备份

mv /etc/apt/sources.list /etc/apt/sources.list.old

默认官方源

cat > /etc/apt/sources.list << EOF
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
EOF

清华源

cat > /etc/apt/sources.list << EOF
deb https://mirrors.tuna.tsinghua.edu.cn/debian/ bullseye main contrib non-free
deb-src https://mirrors.tuna.tsinghua.edu.cn/debian/ bullseye main contrib non-free

deb https://mirrors.tuna.tsinghua.edu.cn/debian/ bullseye-updates main contrib non-free
deb-src https://mirrors.tuna.tsinghua.edu.cn/debian/ bullseye-updates main contrib non-free

deb https://mirrors.tuna.tsinghua.edu.cn/debian/ bullseye-backports main contrib non-free
deb-src https://mirrors.tuna.tsinghua.edu.cn/debian/ bullseye-backports main contrib non-free

deb https://mirrors.tuna.tsinghua.edu.cn/debian-security/ bullseye-security main contrib non-free
deb-src https://mirrors.tuna.tsinghua.edu.cn/debian-security/ bullseye-security main contrib non-free
EOF

中科大源

cat > /etc/apt/sources.list << EOF
deb https://mirrors.ustc.edu.cn/debian/ bullseye main contrib non-free
deb-src https://mirrors.ustc.edu.cn/debian/ bullseye main contrib non-free

deb https://mirrors.ustc.edu.cn/debian/ bullseye-updates main contrib non-free
deb-src https://mirrors.ustc.edu.cn/debian/ bullseye-updates main contrib non-free

deb https://mirrors.ustc.edu.cn/debian/ bullseye-backports main contrib non-free
deb-src https://mirrors.ustc.edu.cn/debian/ bullseye-backports main contrib non-free

deb https://mirrors.ustc.edu.cn/debian-security/ bullseye-security main contrib non-free
deb-src https://mirrors.ustc.edu.cn/debian-security/ bullseye-security main contrib non-free
EOF

腾讯云源

cat > /etc/apt/sources.list << EOF
deb https://mirrors.cloud.tencent.com/debian/ bullseye main contrib non-free
deb-src https://mirrors.cloud.tencent.com/debian/ bullseye main contrib non-free

deb https://mirrors.cloud.tencent.com/debian/ bullseye-updates main contrib non-free
deb-src https://mirrors.cloud.tencent.com/debian/ bullseye-updates main contrib non-free

deb https://mirrors.cloud.tencent.com/debian/ bullseye-backports main contrib non-free
deb-src https://mirrors.cloud.tencent.com/debian/ bullseye-backports main contrib non-free

deb https://mirrors.cloud.tencent.com/debian-security/ bullseye-security main contrib non-free
deb-src https://mirrors.cloud.tencent.com/debian-security/ bullseye-security main contrib non-free
EOF

腾讯云内网源，走内网不消耗公网流量。

cat > /etc/apt/sources.list << EOF
deb http://mirrors.tencentyun.com/debian/ bullseye main contrib non-free
deb-src http://mirrors.tencentyun.com/debian/ bullseye main contrib non-free

deb http://mirrors.tencentyun.com/debian/ bullseye-updates main contrib non-free
deb-src http://mirrors.tencentyun.com/debian/ bullseye-updates main contrib non-free

deb http://mirrors.tencentyun.com/debian/ bullseye-backports main contrib non-free
deb-src http://mirrors.tencentyun.com/debian/ bullseye-backports main contrib non-free

deb http://mirrors.tencentyun.com/debian-security/ bullseye-security main contrib non-free
deb-src http://mirrors.tencentyun.com/debian-security/ bullseye-security main contrib non-free
EOF

阿里云源

cat > /etc/apt/sources.list << EOF
deb https://mirrors.aliyun.com/debian/ bullseye main contrib non-free
deb-src https://mirrors.aliyun.com/debian/ bullseye main contrib non-free

deb https://mirrors.aliyun.com/debian/ bullseye-updates main contrib non-free
deb-src https://mirrors.aliyun.com/debian/ bullseye-updates main contrib non-free

deb https://mirrors.aliyun.com/debian/ bullseye-backports main contrib non-free
deb-src https://mirrors.aliyun.com/debian/ bullseye-backports main contrib non-free

deb https://mirrors.aliyun.com/debian-security/ bullseye-security main contrib non-free
deb-src https://mirrors.aliyun.com/debian-security/ bullseye-security main contrib non-free
EOF

阿里云内网源，走内网不消耗公网流量。

cat > /etc/apt/sources.list << EOF
deb http://mirrors.cloud.aliyuncs.com/debian/ bullseye main contrib non-free
deb-src http://mirrors.cloud.aliyuncs.com/debian/ bullseye main contrib non-free

deb http://mirrors.cloud.aliyuncs.com/debian/ bullseye-updates main contrib non-free
deb-src http://mirrors.cloud.aliyuncs.com/debian/ bullseye-updates main contrib non-free

deb http://mirrors.cloud.aliyuncs.com/debian/ bullseye-backports main contrib non-free
deb-src http://mirrors.cloud.aliyuncs.com/debian/ bullseye-backports main contrib non-free

deb http://mirrors.cloud.aliyuncs.com/debian-security/ bullseye-security main contrib non-free
deb-src http://mirrors.cloud.aliyuncs.com/debian-security/ bullseye-security main contrib non-free
EOF

Linode源（不支持HTTPS）

cat > /etc/apt/sources.list << EOF
deb http://mirrors.linode.com/debian/ bullseye main contrib non-free
deb-src http://mirrors.linode.com/debian/ bullseye main contrib non-free

deb http://mirrors.linode.com/debian/ bullseye-updates main contrib non-free
deb-src http://mirrors.linode.com/debian/ bullseye-updates main contrib non-free

deb http://mirrors.linode.com/debian/ bullseye-backports main contrib non-free
deb-src http://mirrors.linode.com/debian/ bullseye-backports main contrib non-free

deb http://mirrors.linode.com/debian-security/ bullseye-security main contrib non-free
deb-src http://mirrors.linode.com/debian-security/ bullseye-security main contrib non-free
EOF

更新apt索引

apt update