This work aims to obtain a uniform and dense ceramic conversion coating by adding a suitable oxidant to the Zr-Ti basic coating-forming solution and improve the corrosion resistance of AZ80 magnesium alloy. The optimal bath solution was obtained based on the results of salt spray tests and SEM observation; the optimal pH and treatment time were selected according to the polarization curves of the ceramic conversion coating in 3.5%NaCl solution; XRD and XPS were used to analyze the chemical composition of the coating; the corrosion resistance was characterized by salt spray and electrochemical tests. When the mass concentration ratio of the oxidants of KMnO4 and NH4VO3 in the basic bath solution was 3∶1, the pH of the bath solution was 2.5, the treatment time was 3.5 min, and the coating was uniform and dense, which was mainly composed of ZrO2, TiO2, MgO, MgF2 and V2O3. The addition of the oxidants can suppress the adverse effect of the excessively fast hydrogen evolution reaction on the precipitation phases during the coating formation process, and realize the uniform deposition of the coating. The ceramic conversion coating increasess the salt spray resistance time of AZ80 magnesium alloy from 4 h to 48 h. The Zr-Ti ceramic conversion coating with suitable oxidants can significantly improve the corrosion resistance of AZ80 magnesium alloy.