By comparing and analyzing the content distribution of Cr element in 1CrMo alloy laser cladding and submerged arc surfacing, the feasibility of using laser cladding instead of surfacing to modify the surface of rotor journal of 9%Cr steam turbine was studied. The low Cr alloy cladding layer was prepared on the surface of 9%Cr steel by using the semiconductor laser cladding system. Cr content distribution, microstructure and properties of cladding layer were analyzed by direct reading spectrometer, metallographic microscope, scanning electron microscope and micro-hardness tester.1CrMo alloy cladding layers with different thickness and no defects were successfully prepared on the surface of 9%Cr steel by laser cladding technology. The hardness of multi-layer cladding layer is between 220~250HV0.3, which is close to the hardness of matrix. Laser cladding can effectively reduce the dilution matrix of cladding layer, the cladding layer of Cr content reduce obviously, about 2 mm thickness of cladding layer of Cr content is less than 2wt.% of the working face Cr content requirements, and surfacing to 8 mm to achieve the same effect of Cr, laser cladding layers significantly less than the required submerged arc welding method of surfacing welding layer. Compared with the surfacing welding, less cladding layer is needed for the surface modification of the rotor journal of 9%Cr steam turbine.