In order to study the steel bridge pavement shear failure behavior,the 3D discrete element model of steel deck pavement composite structure was established by using discrete element method. The meso parameters of asphalt mortar under 30℃ and 60℃ were calculated by using the Burgers model parameters obtained by DSR test. The interlaminar shear behavior of steel deck pavement under 30℃and 60℃ was simulated and compared with the results of laboratory shear tests. The bond failure between the steel deck pavement and the crack development is analyzed. The results show that the interlaminar shear behavior is simulated well by using the discrete element method. The cracks appear when the bonding between the aggregate unit and the steel plate unit begins to fail,and develop gradually along the interlayer with increasing shear displacement,and finally run through the interface between the steel plate and the pavement. The integrity of the pavement is basically maintained because the bonding failure mainly lies between the steel plate and the pavement layer and there is no bonding failure between the units in the pavement.