Aimed at the problem that old concrete pavement overlayed with asphalt surface is prone to reflective cracking, the paper proposed that the old concrete pavement overlayed with the semi-flexible mixture of cement-foam asphalt should significantly reduce the possibility of surface cracking. In order to guide pavement structure design, the paper studied the mechanical performance of the old concrete pavement by using ANSYS finite-element method , and got the conclusion that the method would significantly reduce the tensile stress and maximum shearing stress in asphalt layer and relieve the cracking of the asphalt pavement. In addition, it would reduce the sensitivity of asphalt surface crack width of the old cement board. The thickness of semi-flexible mixture material paved on the old concrete pavement should not less than 8cm.