The invention belongs to technical field of suction fans and exhaust fans, and particularly relates to a self-cleaning exhaust fan. The self-cleaning exhaust fan comprises a shell, a motor, fan blades, a net cover, a brushing-removing module and a driving module; one side of a rotating shaft of the motor is provided with the brushing-removing module, the brushing-removing module comprises an upperscraping plate and a lower scarping plate, and the upper scraping plate and the lower scarping plate are used for scraping and removing dirt adhered to the surface of the net cover; the other side ofthe rotating shaft of the motor is provide with the fan blades, and the driving module is used for driving the fan blades to rotate; the driving module can be one of a planetary gear mechanism and aconnecting rod mechanism, autorotation and revolution of the fan blades can be achieved, and the net cover is cleaned while air exhausting is conducted; the planetary gear mechanism comprises a firstgear, a second gear and a first gear ring; and the connecting rod mechanism comprises a connecting rod, a third gear and a second gear ring. According to the self-cleaning exhaust fan, the fan bladesand the brushing-removing module are symmetrically arranged on the two sides of the motor, circulating and alternating exhausting and cleaning are achieved through the driving module, the situation that the dirt adheres to the net cover of the exhaust fan is avoided, and manual clearing is not needed.