1. Download the file to a local whl offline, into the c root directory (can be anywhere, but easy to install)
https://pypi.org/
https://www.lfd.uci.edu/~gohlke/pythonlibs/ (recommended to use this address to download the file whl domestic source, fast .ctrl + f find the files they need)
2, cmd file directory to store whl
3, pip install whl offline files
pip install ****.whl
(****. Whl our whl downloaded file name)