In order to optimize the forging process parameters of 5Cr4Mo3VNb die steel, the forging experiments of 5Cr4Mo3VNb die steel were conducted with different initial forging temperatures, final forging temperatures and forging ratios, and the microstructures and mechanical properties of the specimens under different process parameters were analyzed and tested. The results show that when the initial forging temperature increases from 1000 ℃ to 1080 ℃, the final forging temperature increases from 800 ℃ to 900 ℃, and the forging ratio increases from 2 to 10, the average grain size of 5Cr4Mo3VNb die steel specimens first decreases and then increases, and the strength first increases and then decreases. Compared with the specimen at the initial forging temperature of 1000 ℃, the average grain size of specimen is decreased by 40 μm, and the tensile strength and yield strength are increased by 114 and 107 MPa, respectively, when the initial forging temperature is 1060 ℃. Compared with the specimen at the final forging temperature of 800 ℃, the average grain size of specimen is decreased by 21 μm, while the tensile strength and yield strength are increased by 73 and 65 MPa, respectively, when the final forging temperature is 850 ℃. Compared with the specimen at the forging ratio of 2, the average grain size of specimen is decreased by 30 μm, while the tensile strength and yield strength are increased by 97 and 87 MPa, respectively, when the forging ratio is 8. Thus, the optimal initial forging temperature, final forging temperature and forging ratio of 5Cr4Mo3VNb die steel are 1060 ℃, 850 ℃ and 8, respectively.