The electrochemical technique combined with microscopic observation was used to study the anodic polarization of two kinds of steel bar specimens with different surface states in the simulated concrete pore solution, and the change process of corrosion of steel bars under different chloride ion concentrations. The results show that both steel bar without oxide skin and steel bar with oxide skin can passivate in the simulated concrete pore solution, and the stability of the passivation film becomes worse with increasing chloride ion concentration, and the steel bar with oxide skin is more vulnerable to the passivation film. With the same chloride ion concentration, the blunt current of the steel bar with oxide skin is about one order of magnitude larger than that of the steel bar without oxide skin, the corrosion of the steel bar with oxide skin is more serious.