The height of a complex supertall building is 250m. The central RC tube and peripheral SRC frame with two outrigger trusses are employed to resist vertical and lateral loads. It is classified as B grade complex tall building due to the structural characteristic. Due to the over-restriction and complexity of the super tall-building, Pushover Analysis is carried out in order to find it’s behaviors under rare intensity earthquakes. The analytical results demonstrate that the SRC supertall building with high level transfer story possesses good energy-consuming capacity, ductility and ideal yield failure mechanism under rare seismic excitation. Seismic performance of the SRC supertall building is evaluated through Capacity Spectrum Method and good results are obtained.