Laser polishing, as a noncontact green processing technology, can replace the traditional polishing technology. In this paper, the surface of DC53 hardened steel is continuously polished by a laser with a 1064 nm wavelength to investigate the effect of laser polishing on the surface quality of DC53 hardened steel. Additionally, the surface roughness, hardness, Young's modulus, corrosion resistance of the material, and the changes in the subsurface microstructure of the processed surface after laser polishing are thoroughly investigated. The experimental results show that the average roughness is reduced from 4.829 μm to 0.505 μm at a rate as high as 90% when the laser power is 180 W, the laser scan speed is 20 mm/s, and the laser scan interval is 0.06 mm. Simultaneously, the surface hardness and corrosion resistance of the material after laser polishing are reduced compared with the initial sample, the hardness of the molten zone is reduced by 40%, and the self-corrosion potential is reduced by 4%.