The difference of microstructure and corrosion resistance of annealed and variable shape stainless steel matrix during laser processing was studied, master the influence law of laser power on the corrosion resistance of material surface. Laser surface melting treatment using Nd:YAG was done with 316L stainless steel at different heat treatment conditions, electron channeling contrast imaging (ECC) was employed to characterize and analyze the microstructure, and Gamry600 electrochemical workstation was used to experiment the polarization curve and impedance diagram for the sake of studying corrosion resistance evolution during laser surface treatment. 316L stainless steels at annealing condition and deformation condition have similar dynamic potential polarization curve and EIS maps tendency in 3.5wt% NaCl solution. Meanwhile, the fitting data indicated that corrosion potential of laser sample was ?0.438 V (SCE), slightly higher than as-received sample (?0.556 V), but the corrosion current of the laser sample was smaller than that of the as-received sample. It means that laser surface treatment could reduce the corrosion rate of the material surface. The difference is the modification zone on as-draw matrix presented uniform interfacial transition and better binding property than annealing samples. With laser power increasing, the melting arc radius of the 400 W sample was largest, then the polarization curve and EIS map fluctuated in the same magnitude on 200 W and 300 W samples. The corrosion resistance of 316L stainless steel has gradually enhanced after laser surface treatment, while the laser power has no obvious effect on the surface corrosion resistance.