316 stainless steel nano-grain powders were prepared by high-energy ball-milling method. The evolutions of grain size and microstructure of the stainless steel powders with the change of ball-milling conditions were investigated by XRD, SEM. DSC method was used to analyze the oxidation resistance of the powders after ball milling. The law of the change in oxidation weight gain and DSC oxidation peak of samples at the different heating rates were analyzed. Oxidation kinetics studies showed that the oxidant resistance of 316 stainless steel nano-crystalline powder was improved, the activation energy of oxidation reaction increased.