The invention discloses a method for changing the pitch of a lift type impeller. According to the method for changing the pitch of the lift type impeller, a pitch changing connecting rod used for controlling a blade to move is arranged, so that a pitch angle curve of the blade is a sinusoid. By the adoption of the method for changing the pitch of the lift type impeller, the impeller stills keeps good work at an original azimuth angle with high work, and the phenomenon of stall is avoided; in addition, the angle of attack is effectively increased, and efficiency is improved obviously; finally, according to the prior art, a local area is increased, and the efficiency of the local area may be lowered; however, according to the method for changing the pitch of the lift type impeller, the work ability of the area with the largest work is brought into full play, the work ability of the area with the smallest work is fundamentally improved through the pitch changing technology, and the effect is remarkably improved.