Using the double glow plasma surface alloying technique, with the industrial pure iron surface into Cr,Mo,Co and other alloy elements, can be formed on the surface and precipitation hardening stainless steel alloy content and hardness level similar to that of the alloy layer. With SEM studied plasma into the alloy elements alloy layer of surface micro morphology under different process parameters. According to the different temperature, the voltage of the source electrode corresponding to the layer composition and thickness between studies, choose the optimized processparameters: the source voltage is 1 350 V, cathode voltage is 510~530 V, the heating temperature is 1100 ℃, heat preservation time is 5 h.