The PSA oxygen generator uses clean compressed air as the raw material, and the zeolite molecular sieve is used as the adsorbent. The oxygen is obtained at normal temperature by the principle of pressure swing adsorption. According to the difference of the adsorption amount of oxygen and nitrogen in the air on the surface of the zeolite molecular sieve and the diffusion rate of oxygen and nitrogen in the zeolite molecular sieve, the programmable controller is used to control the opening and closing of the pneumatic valve to realize pressure adsorption and decompression desorption. The process of completing the separation of oxygen and nitrogen to obtain oxygen of the desired purity.