<p>The influence mechanism of Cu on the corrosion process of low-carbon steel in the salt spray environment has been investigated. In the early stages of corrosion, a Fe-Cu galvanic cell formed between the Fe matrix and Cu, which accelerated the corrosion of Fe. As the Fe continues to corrode, Cu is exposed, losing the cathodic protection of Fe and being oxidized to Cu²⁺, which migrates along the pores of corrosion products onto the surface of the matrix, and is reduced to elemental Cu at the cathode of the Fe-Cu galvanic cell and deposited on the surface of the steel. With the increase in the amount of Cu deposited, a protective film was formed, isolating the metal matrix from O₂ and H₂O in the corrosive medium, and decreasing the corrosion rate. Therefore, the corrosion mechanism of oxidation–reduction of Cu for Cu-containing steel is proposed in this paper. Additionally, combining with the three corrosion mechanisms previously proposed by the team, a detailed parameterization and simulation analysis of the corrosion process for Cu containing steel was studied using cellular automata. The simulation results successfully replicated the dynamic evolution of Cu corrosion behavior in low-carbon steel.</p>