Aiming at the process problems of poor surface quality of metal laser 3D printing, laser cladding and other laser deposition forming processes, it is difficult to directly install the machine, using a fiber-semiconductor coupled laser to polish the iron-based laser cladding layer. The influence of laser polishing on the surface morphology and physical and mechanical properties of laser deposition forming was studied. Firstly, the macroscopic morphology and roughness of the laser polishing cladding were tested, analyzed and characterized by hand-held microscope and white-light interferometer. Then, the microstructure of the cladding layer was tested and analyzed by scanning electron microscope (SEM). The microhardness value of the cladding layer along the depth direction was tested by X-ray stress tester. The results show that laser polishing cladding macroscopic morphology is smooth and the roughness of the laser cladding layer is significantly reduced. The effects of different polishing times on the surface quality is compared. After the first polishing, the microstructure of the middle of the cladding layer is planar cell crystal, and the microstructure of the middle of the cladding layer is the fine equiaxed crystal after two times polishing. The surface residual stress of the cladding layer is compressive stress after the first polishing, the surface residual stress of the cladding layer is tensile stress after the two times polishing. After two times of polishing, the microhardness is 1.3 times higher than the original cladding and 3.5 times higher than that of the substrate.