Based on the extended finite element method（ XFEM）,the dynamic propagation behaviors of interface cracks and sub interface cracks in bimaterials are studied. A dynamic growth analysis model of bimaterial plate with interface crack and sub interface crack is established. In this model,the centralized mass matrix is used to replace the traditional consistent mass matrix to improve the efficiency,and the Newmark method is used for time integration. This model is compared with the dynamic response and energy value calculated by the two-dimensional elastic model established in the finite element software. Through numerical examples,the effects of strain rate and material properties on the interface and sub interface crack growth in circular and linear bimaterials are studied.