Self-cleaning exhaust hood and control method thereof

The invention relates to a self-cleaning exhaust hood and a control method thereof. The self-cleaning exhaust hood comprises a fume collecting hood, a filter net, a fume guiding plate, a fan, an air outlet hood and an air guiding pipe, the fume guiding plate can ascend to seal an air inlet of the fume collecting hood, and a liquid inlet valve capable of adding a cleaning medium into a cavity defined by the fume guiding plate and the fume collecting hood is arranged on the fume collecting hood; a first air outlet and a second air outlet are formed in the air outlet hood, and a switching mechanism allowing only one of the first air outlet and the second air outlet to be opened or closed is arranged in the air outlet hood; and the first end of the air guiding pipe is connected with the secondair outlet, and a ventilation opening connected with the second end of the air guiding pipe is formed in the fume collecting hood. In use, the cleaning medium is input into the inner cavity defined by the fume guiding plate