The box structure is a typical underground protective structure, whose mechanical response to explosion seismic is of great interest in protection engineering. In this work, the rectangular force and combining dynamic and static methods have been employed to identify the mechanical behavior of deep underground structure under explosion seismic. The effects of ratio of side length, the incident angle, surrounding properties etc. were considered and the mechanical model which can describe the interaction between structure and soil was also developed. Finally, the dynamic response of box-type structure was analyzed.