Noise-reducing and energy-saving device for hair dryer

The invention relates to a noise-reducing and energy-saving device for a hair dryer. The noise-reducing and energy-saving device for the hair dryer comprises an outer layer (1) and an inner layer (2), wherein the outer layer (1) is a non-porous silencing metal plate; the inner layer (2) is a silencing metal plate with a plurality of through holes (21); the outer layer (1) and the inner layer (2) are arranged in parallel; a resonant cavity is formed between the two parallel silencing metal plates; air in the cavity has elasticity and is equal to a spring; an air column in the aperture does reciprocating motion like a piston; and due to the damping action of the neck wall on the air, part of sound energy is converted into heat energy. When the frequency of incident sound wave is consistent with the inherent frequency of the resonant cavity, the resonance phenomenon occurs, the air column in the aperture has the maximum motion amplitude on the aperture wall of the hole, the sound energy is converted into heat en