参考这里：https://wiki.debian.org/iwlwifi

Debian 9 "Stretch"

1. Add a "non-free" component to /etc/apt/sources.list, for example:

   # Debian 9 "Stretch"
   

   deb http://httpredir.debian.org/debian/ stretch main contrib non-free
   

2. Update the list of available packages and install the firmware-iwlwifi package:

   sudo apt-get update
   
   sudo apt-get install firmware-iwlwifi

3. As the iwlwifi module is automatically loaded for supported devices, reinsert this module to access installed firmware:

   su -
   
   modprobe -r iwlwifi
   
   modprobe iwlwifi
   

4. Configure your wireless interface as appropriate.

Debian 8 "Jessie"

1. Add a "non-free" component to /etc/apt/sources.list, for example:

       # Debian 8 "Jessie"

deb http://httpredir.debian.org/debian/ jessie main contrib non-free

2. Update the list of available packages and install the firmware-iwlwifi package

apt-get update && apt-get install firmware-iwlwifi

1. As the iwlwifi module is automatically loaded for supported devices, reinsert this module to access installed firmware:

   su -
   
   modprobe -r iwlwifi
   
   modprobe iwlwifi