Anomalistic architecture especially overhanging structure has become a trend of architectural development, Based on the characteristics of a large vertical eccentric, more prominent facade and strong reverse effect,overhanging structure is often serious super-norm and extremely detrimental to the seismic design[1], Now it has become an important part of seismic review. By the analysis and comparison on the coupling of the translational and torsional seismic response from ANSYS program[2]. The behavior of seismic catastrophe of cantilever building structure is studied under bi-directional earthquake action and the change law of cantilever member with the length is obtained, the suggestions on engineering design are put forward for future seismic design of such structures.