Abstract: The large deformation elasticplastic theory and the software of ANSYS5 5 were used to study the process of the hydrostatic extrusion for the tungsten alloys. The calculation model was established, and the variation laws of the stress strain in the sample were obtained. And the reason why the defects occur during the process of hydrostatic extrusion was inquired into. The method of the optimum design for the process of hydrostatic extrusion for tungsten alloy was proposed. The results have directive purport on experiments.