The effect of polyphosphoric acid(PPA) on elastic deformation recovery ability of matrix asphalt, SBS and SBR modified asphalts was analyzed by repeated creep recovery test. Through penetration shear test, semi circular bending test and fatigue bending test, the pavement performance of matrix asphalt mixture, SBS and SBR modified asphalt mixtures was studied. Finally, the fatigue properties of different asphalt mixtures were analyzed by Weibull distribution at different failure probabilities. The results show PPA can significantly increase the viscosity of asphalt, and PPA has less influence on the elastic deformation recovery ability of asphalt, but SBS can greatly improve the elastic recovery of asphalt; PPA has a significant effect in improving shear stability at high temperature; The negative effect of PPA on the low temperature performance of asphalt mixture can be[23] effectively compensated by compositing SBS or SBR, and PPA can increase to a certain extent anti fatigue properties of asphalt mixtures.