Through the experimental study of 316L stainless steel laser cladding repair on the surface of 300M steel,the structure and properties of the laser cladding repair layer were discussed.On the basis of previous experiments,this paper selected 316L stainless steel powder as cladding material to carry out variable power laser cladding comparative experimental research.By means of metallographic analysis,EDS analysis,XRD analysis and electrochemical analysis,the effects of different laser power on the microstructure,microhardness and corrosion resistance of the coating were analyzed.The results show that when the laser power is 1.5 kW,the coating quality is the best,and the cladding layer and the substrate are metallurgically bonded.The bottom of the cladding layer is planar crystal structure,the lower part of the cladding layer is cellular crystal and columnar crystal,and the upper part is dendrite and equiaxed crystal,the surface layer is mainly equiaxed crystal structure.When the laser power is 1.5 kW,the maximum hardness of the cladding layer is 2.5～3 times of the matrix hardness,which is more suitable for actual working conditions with friction and impact,additionally,the coating has the lowest corrosion potential (-462.65 mV)and the minimum self corrosion current (3.63×10 -3 mA),so its corrosion resistance is the best.The impedance of cladding coatings with different laser power was ranked as:1.5 kW>2.0 kW>1.0 kW.