The invention discloses a device for cleaning glass. The device for cleaning the glass comprises a rack, a conveying device, CCD cameras, a cleaning device, an air knife and a controller; a waste water pool is arranged at the bottom of the rack; the conveying device comprises a driving wheel, a driven wheel and a conveying belt; the driving wheel is driven by a first motor; the CCD cameras are evenly distributed on an inlet of the conveying device; the cleaning device comprises a washing spraying head and a plurality of cleaning brush heads, and the washing spraying head is installed on the top of a support and connected with a water storage pool through a water pipe and a water pump; the multiple cleaning brush heads are arranged in parallel in the movement direction of the conveying device and connected with automatic telescopic rods driven by a motor; the air knife is installed on an outlet of the conveying device; and the controller is electrically connected with the CCD cameras, the first motor, the water pump, the motor driving the automatic telescopic rods and the air knife. The device for cleaning the glass is simple in structure, good in cleaning effect and capable of automatically selecting the different cleaning heads to clean the glass according to different sizes and cleanness degrees of to-be-cleaned glass.