In order to solve the crack propagation problem of concrete gravity dam with multiple initial notches, the extended finite element method and the cohesive crack model were applied to numerical simulation on the finite element analysis software of ABAQUS. The path of multiple cracks propagation and the load-crack opening displacement of the main crack were analyzed. The results show that the path of multiple cracks propagation in concrete gravity dam is almost consistent with the results of the literature, and the load-crack opening displacement curve of the main crack has a little difference between them. It is concluded that the application of the extended finite element method can accurately simulate the whole process of multiple cracks in concrete gravity dam from loading to instability failure without having to remesh and reduce the computation, providing an effective application way to solve practical engineering problems.