Abstract: The equilibrium adsorption characteristics of nitrogen adsorbents were tested and a suitable nitrogen adsorbent was selected for producing oxygen by rapid vacuum pressure swing adsorption. Due to low oxygen concentration in the product obtained by traditional rapid pressure swing adsorption,an improved pressurization step with raffinate was developed and experimentally studied in a rapid vacuum pressure swing adsorption system for producing oxygen. The results show that combined pressurization with raffinate and feed gas can effectively improve the oxygen concentration in the product during the rapid vacuum pressure swing adsorption process. The pressure and oxygen concentration of raffinate for pressurizing are key parameters to influence the oxygen concentration in the product,and a higher concentration oxygen product can be obtained by taking an appropriate pressure and a higher oxygen concentration of raffinate. The 90% oxygen can be generated by combined pressurization with raffinate and feed gas during the rapid vacuum pressure swing adsorption process with an adsorption pressure of 240 k Pa and a desorption pressure of 60 k Pa,and the adsorbent productivity is 325. 08 L·h^-1·kg^-1.