In order to improve aderverse state of connection between cement concrete pavement and base layer, the black substratum of asphalt concrete was set between pavement and base layer. According to the elastic mechanics theory, 3d finite element model of pavement structure was established, the vertical displacement of each structure layer was analyzed by using ANSYS. The results show that black substratum can absorb part of deformation energy by using its good deformation ability, so as to improve the stress condition of the entire pavement structure. It can increase the ability of structure layer deformation coordination to set the black substratum, which can make rigid pavement combine the characteristics of rigid pavement and flexible pavement.