The work aims to obtain optimum process parameters of manganese phosphating film on 38MnVS steel by studying influence of phosphating temperature and time on morphology, film thickness and corrosion resistance of 38MnVS steel. Manganese phosphating film was prepared on the surface of 38MnVS provided with different phosphating temperature and time by controlling single-factor variables. Morphology, film thickness and corrosion resistance of 38MnVS steel phosphating film were analyzed using scanning electron microscope (SEM), thickness gauge and performing bronze sulfate pitting test. The phosphating film was heterogeneous nucleation and first formed on scratches and grain boundaries. As phosphating time prolonged, grains of the phosphating film covered the substrate surface quickly, and both film thickness and corrosion resistance increased continuously. Performance of the phosphating film changed slightly when phosphating time exceeded 15 min. At the phosphating temperature of below 75 ℃, growth of the film was inhibited, the film failed to cover the substrate, and the film thickness and corrosion resistance were low. As the phosphating temperature rose, the grains grew continuously, thickness and corrosion resistance increased rapidly. At the phosphating temperature of over 95 ℃, performance of the film increased slowly. The optimum phosphating process of 38MnVS steel is 85 ℃ and 15 min.