Research conclusions :(1) The method using the average stress ratio as the removing index of the importance coefficient is feasible which shows that this method is not only suitable for frame structure，but also can be extended to long - span space structure. (2) Static analysis method is more feasible than dynamic analysis method， but may lead to more conservative results. (3) After the failure of the side arch column，side arch local regional failure occurred， large displacement and rotation angle bar appeared. This shows that side arch column is an important part of the structure and should focus on the protection of the side column in the use process. (4) Some bars of vault near central cantilever end rupture，but dont spread. So this section should be protected in the actual design. (5) The research result about the mode and mechanism of building continuous collapse，can provide a reference and guidance for the anti - explosion and design of the similar station buildings.