40Cr13 plastic die steel was quenched at different temperatures (960,1 020,1 080,1 140 ℃), and the effect of quenching temperature on microstructure and hardness was studied. The steel was tempered at 200 ℃,and the corrosion resistance of the steel was studied by immersion test and electrochemical test. The results show that the microstructure of the test steel after quenching at different temperatures was composed of quenched martensite, carbides and a small amount of retained austenite. The microstructure became coarse with increasing quenching temperature, and the number of carbides decreased. When the quenching temperature was 1 140 ℃, network carbides precipitated on austenite grain boundaries in the microstructure. The hardness of the test steel increased first and then decreased with increasing quenching temperature. When the quenching temperature increased from 960 ℃to 1 080 ℃, the corrosion rate of the test steel after tempering in FeCl3 solution decreased; the diameter and depth of pitting holes on the surface of the test steel decreased, and the number increased. The free-corrosion potential of the test steel in NaCl solution increased, and the free-corrosion current density decreased; the corrosion rate decreased and the corrosion tendency decreased. The optimum the quenching temperature was 1 020 ℃; at this point, the quenched martensite was relatively small, and the hardness was the largest; the corrosion resistance was relatively good.