To analyze failure mechanism and internal essence of macro-mechanical properties difference for crumb rubber asphalt micture, discrete element models are established, contact force vector diagram, force chain network chart and contact force local enlarging graphs belong to gap gradation crumb rubber asphalt mixture, continuous grading crumb rubber asphalt mixture and asphalt mixture are systematically studied firstly, their internal strength chain, weak force chain and deformation characteristics are obtained respectively, their bearing capacity sorting and deformability sorting are proposed. Then, local enlarged drawing in adhesive contact failure position and displacement vector map of crumb rubber asphalt mixture are deeply researched, failure mechanism of crumb rubber asphalt mixture is obtained. The results show that their bearing capacity from big to small in proper order is asphalt mixture, gap gradation crumb rubber asphalt mixture, continuous grading crumb rubber asphalt mixture. Their deformability from big to small in proper order is asphalt mixture, gap gradation crumb rubber asphalt mixture, continuous grading crumb rubber asphalt mixture.