First, obtain the qBittorrent source code. Either download and extract a .tar archive from Sourceforge or clone this git repo (git clone https://github.com/qbittorrent/qBittorrent). 
Enter the folder in a new terminal window and run:

 ./configure --prefix=/usr --disable-gui
 make

Note1: If you're using libtorrent-rasterbar from the 0.16.x series, you also need to pass the "--with-libtorrent-rasterbar0.16" option to configure. qBittorrent v3.3.x has dropped the support of libtorrent 0.16.x. 
Note2: If you want to compile with qt4 instead of qt5, you also need to pass the "--with-qt4" option to configure. 
Note3: If you want to disable ALL authentification on the WebGUI, change some lines as explained here: https://github.com/qbittorrent/qBittorrent/wiki/Disable-authentification-of-webGUI/

And finally to install qBittorrent:

 sudo make install

That's it! qBittorrent-nox should now be installed. You can now run qBittorrent-nox using the following command:

 qbittorrent-nox

Since you disabled the graphical user interface, qBittorrent can only be controlled via its Web UI. If you haven' t disabled authentification, as a default, you can access it from:

 http://localhost:8080
 Username: admin
 Password: adminadmin

A documentation about running qBittorrent without GUI is available here.

via。https://github.com/qbittorrent/qBittorrent/wiki/Compiling-qBittorrent-on-Debian-and-Ubuntu