Abstract: In the paper, based on the nonlinear property of granular base, the superposition method of multilayer elastic system analysis is employed to analyse surface deflection, flexural tensile stress at the bottom of asphalt surface layer and semi rigid base course. Simultaneously, the relationship between thickness and fatigue life of pavement is established. Eventually, the thickness of semi rigid pavement with granular base, which is suitable for heavy traffic and shows excellent performance of resistance to fatigue, is proposed.