The invention provides a muffler plate, a motor and an air conditioner. The muffler plate comprises a plate body and a medium channel arranged inside the plate body. The two ends of the medium channel penetrate through the surface of the plate body, and a medium inlet and a medium outlet are formed. The medium channel comprises a reducer. In the medium flowing direction, the cross section area of the reducer is gradually increased. According to the technical scheme, the problem that in the prior art, working noise of a compressor is large is solved.