The invention discloses an ultrasonic self-cleaned extractor hood and a method thereof. The ultrasonic self-cleaned extractor hood comprises a controller, a machine shell and a centrifugal fan arranged in the machine shell. A cleaning liquid sucking and discharging pump and a cleaning liquid sucking and discharging port are formed in the machine shell. One connector of the cleaning liquid sucking and discharging pump communicates with the cleaning liquid sucking and discharging port through a pipeline. The other connector of the cleaning liquid sucking and discharging pump directly communicates with the bottom of a volute through a pipeline. At least two through holes are formed in the bottom of the volute. Ultrasonic transducers are fixed to the lower sides of the through holes. The fan, the cleaning liquid sucking and discharging pump and the ultrasonic transducers are connected with the controller. The problem that an extractor hood in the prior art is hard to clean or the cleaning effect is not ideal is effectively solved. The ultrasonic self-cleaned extractor hood is high in automation degree, automation cleaning of the extractor hood is truly achieved, and very high practical value is achieved.