debian 9 源：

163源：

cat << EOF > /etc/apt/sources.list
deb http://mirrors.163.com/debian/ stretch main non-free contrib
deb http://mirrors.163.com/debian/ stretch-updates main non-free contrib
deb http://mirrors.163.com/debian/ stretch-backports main non-free contrib
deb-src http://mirrors.163.com/debian/ stretch main non-free contrib
deb-src http://mirrors.163.com/debian/ stretch-updates main non-free contrib
deb-src http://mirrors.163.com/debian/ stretch-backports main non-free contrib
deb http://mirrors.163.com/debian-security/ stretch/updates main non-free contrib
deb-src http://mirrors.163.com/debian-security/ stretch/updates main non-free contrib
EOF

中科大源：

debcat << EOF > /etc/apt/sources.list
deb https://mirrors.ustc.edu.cn/debian/ stretch main contrib non-free
deb-src https://mirrors.ustc.edu.cn/debian/ stretch main contrib non-free
deb https://mirrors.ustc.edu.cn/debian/ stretch-updates main contrib non-free
deb-src https://mirrors.ustc.edu.cn/debian/ stretch-updates main contrib non-free
deb https://mirrors.ustc.edu.cn/debian/ stretch-backports main contrib non-free
deb-src https://mirrors.ustc.edu.cn/debian/ stretch-backports main contrib non-free
deb https://mirrors.ustc.edu.cn/debian-security/ stretch/updates main contrib non-free
deb-src https://mirrors.ustc.edu.cn/debian-security/ stretch/updates main contrib non-free
EOF

阿里云源:

cat << EOF > /etc/apt/sources.list
deb http://mirrors.aliyun.com/debian/ stretch main non-free contrib
deb-src http://mirrors.aliyun.com/debian/ stretch main non-free contrib
deb http://mirrors.aliyun.com/debian-security stretch/updates main
deb-src http://mirrors.aliyun.com/debian-security stretch/updates main
deb http://mirrors.aliyun.com/debian/ stretch-updates main non-free contrib
deb-src http://mirrors.aliyun.com/debian/ stretch-updates main non-free contrib
deb http://mirrors.aliyun.com/debian/ stretch-backports main non-free contrib
deb-src http://mirrors.aliyun.com/debian/ stretch-backports main non-free contrib
EOF

debian 10 源：

163源：

cat << EOF > /etc/apt/sources.list
deb http://mirrors.163.com/debian/ buster main non-free contrib
deb http://mirrors.163.com/debian/ buster-updates main non-free contrib
deb http://mirrors.163.com/debian/ buster-backports main non-free contrib
deb http://mirrors.163.com/debian-security/ buster/updates main non-free contrib
deb-src http://mirrors.163.com/debian/ buster main non-free contrib
deb-src http://mirrors.163.com/debian/ buster-updates main non-free contrib
deb-src http://mirrors.163.com/debian/ buster-backports main non-free contrib
deb-src http://mirrors.163.com/debian-security/ buster/updates main non-free contrib
EOF

中科大源：

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

阿里云源：

cat << EOF > /etc/apt/sources.list
deb http://mirrors.aliyun.com/debian/ buster main non-free contrib
deb http://mirrors.aliyun.com/debian-security buster/updates main
deb http://mirrors.aliyun.com/debian/ buster-updates main non-free contrib
deb http://mirrors.aliyun.com/debian/ buster-backports main non-free contrib
deb-src http://mirrors.aliyun.com/debian-security buster/updates main
deb-src http://mirrors.aliyun.com/debian/ buster main non-free contrib
deb-src http://mirrors.aliyun.com/debian/ buster-updates main non-free contrib
deb-src http://mirrors.aliyun.com/debian/ buster-backports main non-free contrib
EOF

替换方法：

# 默认源替换为163源：
sed -i 's#http://deb.debian.org#http://mirrors.163.com#g' /etc/apt/sources.list

# 163替换为阿里云源：
sed -i 's#http://mirrors.163.com#https://mirrors.aliyun.com#g' /etc/apt/sources.list

# debian9替换为10源：
sed -i 's/stretch/buster/g' /etc/apt/sources.list

刷新源：

apt update