Abstract: The optimal adsorption sites of Cl atoms on α-Fe(100) surface doped with Cu and Sb under different coverage levels were determined with the use of ab-initio molecular dynamics(AIMD) simulations and density-functional theory(DFT) calculations. The results showed that both the doping elements and the coverage levels significantly affected the optimal adsorption sites of Cl atoms. The doping of Cu or/and Sb could obviously weaken the surface adsorption of Cl atoms,and the single doping of Sb was superior to the single doping of Cu in effectiveness of weakening adsorption of Cl. The co-doping of Cu and Sb made it possible to promote the charge exchange between these two elements and Cl,thus rendering the corrosion resistance of co-doped α-Fe(100)surface superior to that of single-doped α-Fe(100) surface.