Calculation of structural course thickness is the primary task in pavement design. It will directly influence the mechanical properties, service life and the cost of pavement structure. Using BISAR3 of SHELL design method, the impacts of structural course thickness on the mechanical properties and service life of heavy load semi-rigid asphalt pavement structure were analyzed systematically. And the influencing laws of the thickness of surface course, base course and sub-base course on heavy load semi-rigid asphalt pavement service life were also discussed. According to the results of sensitivity analysis of structural course thickness and axle loads, a prediction model of service life of heavy load semi-rigid asphalt pavement was proposed. These achievements can contribute to determine the rational structural course thickness of semi-rigid asphalt pavement and ensure the service life of pavement consistent with the cost.