The PSA pressure swing adsorption air separation nitrogen generator uses compressed air as raw material, uses a new type of adsorbent carbon molecular sieve, and uses the principle of pressure swing adsorption to separate oxygen and nitrogen in the air at room temperature, thereby obtaining nitrogen with a purity greater than 99%. This device has the advantages of simple structure, easy operation, ready-to-use and low energy consumption. It is widely used in protective atmosphere for heat treatment of metal materials and mechanical parts; nitrogen-filled protective atmosphere in the production processes of synthetic fibers, petrochemicals, float glass, etc. Oxidation; food preservation; grain storage, Chinese medicine preservation, tea color preservation, etc.