Abstract: Large flow reverse osmosis (RO) water purifier, without water tank, can reach 1.0L/min or over 1.0L/min, can well meet the daily drinking water and water needs of users, very popular with consumers. However, the noise of large flow reverse osmosis (RO) water purifier is large, and the noise is more than 50dB(A) , which directly affects the user's feel. Purifier noise mainly comes from pump, waste water valve, pipeline vibration and so on. Through noise reduction treatment of noise source and noise propagation path, purifier noise can be effectively reduced.