Superpave Gyratory Compactor (SGC) is used to design high quality mix asphalt specimen. In this research the structure of the SGC was analyzed, and the methods used in the Stewart mechanism are adopted. Based on the hypothesis that the parts made up of the mechanism are rigid body, no deformation exists in the connecting rods. Equations are deduced and the position is presented. The positions of the joint are acquired from the equations by MATLAB. Finally the elements that affect the title angle between the swivel panel and the perpendicular z axis are calculated, and the optimal parameters are presented.