Based on the urgent demand of aerospace products for super-high strength and toughness rare earth magnesium alloy component， the isothermal forging forming technology was adopted in this paper， the forging process characteristics of VW84M rare earth magnesium alloy were studied. The forging process properties of VW84M high strength and toughness rare earth magnesium alloy were studied， the process structure characteristics of the straight cylinder were analyzed， the forging process of the straight cylinder was established， the forming process of straight cylinder section was studied by three-dimensional modeling， numerical simulation and forming process experiments， the forgings were produced by forming process test. The results showed that VW84M rare earth magnesium alloy has good plastic forming performance at 440 ℃ forging temperature and suitable extrusion speed， and the material has practical engineering application ability.The extrusion load obtained by numerical simulation is 64.72 MN， and the actual extrusion load is 60 MN， with a difference of 7.8%， the shear and axial mechanical properties were better than the requirement with tensile strength not less than 340 MPa， yield strength not less than 210 MPa and elongation not less than 6%.The metal streamline distribution of the straight cylinder is uniform， and the tangential mechanical property is better than the axial one.