The initial forging temperature, final forging temperature, heating temperature, holding time, forging force, forging speed and forging times of high-strength magnesium alloy Mg-9Gd-5.5Y-2Zn-0.6Mn specimens for automobile were adjusted and optimized. The initial forging temperature is increased from 430 ℃ to 450 ℃, the final forging temperature is decreased from 360 ℃ to 330 ℃, the heating temperature is increased from 430 ℃ to 450 ℃, the holding time is extended from 30 min to 40 min, the forging force is reduced from 680 kN to 630 kN, the forging speed is increased from 20 mm·min-1 to 25 mm·min-1, and the forging times are increased from 1 to 2 times, and the microstructure and mechanical properties of the alloy specimens before and after the optimization of forging process parameters were tested and compared. The results show that the microstructure of high-strength magnesium alloy Mg-9Gd-5.5Y-2Zn-0.6Mn specimen is significantly refined after optimizing the process parameters, and the elongation after fracture of the alloy specimen is 7.1%, which is basically unchanged compared with that before the optimization. The tensile strength is 425 MPa, and the yield strength is 342 MPa, which are increased by 37 MPa and 32 MPa, respectively, compared to those before the optimization.