The invention discloses a plane cleaning device and method. The device comprises a base, wherein a driving motor is mounted on the base, output of the driving motor is connected with a brush through a speed reducing mechanism, the brush is matched with a to-be-cleaned plane, the to-be-cleaned plane is cleaned through rotation of the brush, and rolling wheels are connected at the bottom of the base. According to the method, brushing by the aid of the brush is realized through the driving motor, the rolling wheels are driven to move by a traveling driving motor, through plane cleaning work of a sweeping liquid spraying device and a wiping device, the dirty surface cleaning effect is greatly improved, the working efficiency is improved, the workload of workers for scrubbing is reduced, and the device is very applicable to large-scale CSP (concentrating solar power) mirror field lens occasions.