Laser rescaling is an effective way to reduce the surface corrosion of marine steel. The differences in laser rescaling parameters will result in differences in the descaling effect and corrosion performance. Therefore, it is necessary to examine the change in the corrosion performance after laser rescaling. This study used EH36 marine steel as the research object and examined the influence of parameters, such as laser energy density and scanning speed, on the corrosion resistance and changes in surface morphology and elemental composition. Additionally, the mechanism of the influence of laser parameters on corrosion performance was evaluated, and on this basis, the optimal laser rescaling process for corrosion resistance was determined. Results shows that the corrosion resistance of EH36 steel first increased and then decreased with the increase of laser energy density and scanning speed. The oxygen content of the surface met the corrosion resistance requirements under the optimal parameters. When the laser energy density was 3.820 J/cm², the excessive laser energy ablated the substrate. The grain size of the metal substrate decreased. Grain refinement and the density of active sites at the grain boundaries became higher, which facilitated the dissolution of the metal and reduced the stability of the corrosion products on the metal surface, thereby reducing the corrosion resistance. The surface of EH36 steel treated with a laser energy density of 2.546 J/cm² and scanning speed of 3000 mm/s exhibited optimal corrosion resistance, with a 57% decrease in corrosion current density compared to the original steel.