hrough the ion nitriding treatment of 316L austenitic steel at four different temperatures, and the metallographic, scanning, XRD and electrochemical tests of the nitriding samples, the results are compared and analyzed, and the influence of different nitriding temperatures on the structure and properties of the nitriding layer on the surface of 316 L stainless steel is revealed. After 450℃ nitriding, the samples have the highest hardness, the best corrosion resistance and the best uniformity of nitriding layer and boundary layer. Furthermore, it is preliminarily judged that the formation and decomposition of S phase is a dynamic process during nitriding, both of which are carried out at the same time. Under 450℃ S the formation speed of the phase is obviously larger than the decomposition speed, which makes the comprehensive performance of the sample best.