Download the appropriate version of install_flash_player.tar.gz archive from the official website
Unpack the downloaded file, and copy the file libflashplayer.so into the Chrome plugins directory:
sudo cp libflashplayer.so /opt/google/chrome/plugins/
Note If the plugins directory is not existed, you should create it.
Open the address “chrome://plugins/” in your Chrome, if all goes well, you should see the flash plugin information like this::
Flash - Version: 11.2 r202 Shockwave Flash 11.2 r202
Now the latest flash has been activated in you Chrome.