The corrosion simulation model of the typical seawater piping system is established by using COMSOL, which is the multi-physical field coupling evaluation software, in order to research the corrosion mechanism and the anti-corrosion optimization of the marine B10 seawater piping system. According to the distribution of flow rate, streamline, pressure, oxygen concentration and corrosion rate, it is found that the flow rate has a great impact on the distribution of the oxygen concentration, resulting in the galvanic corrosion of oxygen concentration difference. Three anti-corrosion optimization methods are proposed in view of the weakness of the pipe corrosion in the simulation calculation, including the appropriately increase of the bending curvature of the elbow, the cathodic protection of the steel straight pipe section coupled with the B10 pipe, and the installation of steel bellows in front of the equipment. It provides solutions for the life extension of the marine B10 seawater piping system.