The process is two towers. After the raw air is pressurized by the compressor, it passes through the air pretreatment device to remove oil, dust and other solid impurities and water, and is cooled to normal temperature. The processed compressed air enters the adsorption tower equipped with molecular sieves through the air inlet valve. Nitrogen, carbon dioxide, etc. are adsorbed, and the outflowing gas is high-purity oxygen. When the adsorption tower reaches a certain degree of saturation, the inlet valve is closed, the flushing valve is opened, and the adsorption tower enters the flushing stage. Afterwards, the flushing valve is closed and the desorption valve is opened. Entering the desorption and regeneration stage, thus completing a cycle.