Using the characteristics of dual-directional extrusion and sprial deformation, a new extrusion technique of dual-directional extrusion and sprial compound deformation was proposed. Effect of sprial angle and groove radius on the accumulated strain of the deformed billet was analyzed by using DEFORM-3D software, the proper structure parameters were obtained, and the actual die was manufactured for experimental research. The research results show that the dual-directional extrusion and sprial compound deformation can greatly improve the effective strain of magnesium alloy, with the increase of sprial Angle and groove radius, the effective strain value is increased accordingly, however, the degree of strain inhomogeneity grows. Spiral angle of 40 ° and groove radius of 0.8 mm can obtain superior equivalent strain value and uniform equivalent strain distribution, and grain structure is refined dramatically.