A window cleaning robot (100), a window cleaning robot system and a method for controlling the window cleaning robot are disclosed. The window cleaning robot (100) comprises a window cleaning robot body (10), a detecting module disposed on the window cleaning robot body (10) and configured to detect an environment outside the window cleaning robot body (10), and a controlling device connected to the detecting module and configured to control an action of the window cleaning robot body (10) based on a data detected by the detecting module.