In this paper, 4Cr5MoSiV1 steel is dealt with by QPQ salt-bath nitriding at 520°C, 540°C, 560°C and for 2h、4h、6h, respectively. The treated surface microstructure was analyzed by using SEM. The depth of nitriding layer, scratch hardness and wear-resistance were tested for QPQ salt-bath nitriding technology. The corrosion resistance was tested in the 5%NaCl water by using spraying method. The experimental results indicate that with increasing the temperature and the nitriding time, the depth of nitriding layer, scratch hardness and wear-resistance of 4Cr5MoSiV1 steel were increased greatly. Comparing with the untreated specimen, its hardness enhances 196.73%, wear resistance enhances 349.65%, anti-corrosion enhances 943.10%. The die hardness, wear resistance and the corrosion resistance can be greatly improved by using the QPQ salt-bath nitriding technology.