Nitrogen making machine is a nitrogen making equipment designed and manufactured according to pressure swing adsorption technology. The nitrogen making machine uses high quality imported carbon molecular sieve (CMS) as adsorbent and adopts pressure swing adsorption principle (PSA) at normal temperature to separate air and produce high purity nitrogen. Two adsorption towers are usually used in parallel, and the imported pneumatic valve is controlled by an imported PLC to operate automatically, alternately perform pressure adsorption and decompression regeneration, complete the separation of nitrogen and oxygen, and obtain the required high purity nitrogen.