Abstract: The current major simulation methods for building structure collapse were summarized and these methods were grouped under four heads: pre-specified damage and failure criteria, implicit finite element method, explicit finite element method and discrete element method. The corresponding development histories were introduced, respectively. And the defects and problems were discussed which appearing in the building simulation by these methods. Based on the basic principle and characteristic of the discrete element method for particle materials, its advantages were analyzed in the simulation of structure collapse. Then by taking a 3-span, 10-floor senior frame structure under horizontal strong impact as an example, a program based on PFC2D was written and a particle flow model was developed to simulate the whole dynamic process from structural member cracking, fracture and failure to part collapse of structure and whole collapse. In the end, the directions and problems to the further study were brought forward.