Nitrogen plant is a high-tech and energy-saving separation technology to produce nitrogen directly from air at room temperature. It is a high-tech and energy-saving separation technology to produce nitrogen directly from air at room temperature. It utilizes the compressed air after a series of purification by removing oil, water and dust to separate the nitrogen production under the action of variable pressure adsorption. Due to the kinetic effect, the diffusion rate of oxygen on the carbon molecular sieve is obviously higher than that of nitrogen, and when the adsorption has not reached the equilibrium, the nitrogen is enriched in the gas phase, and it adopts the imported PLC automatic control technology to realize the continuous production of high-quality nitrogen gas.