Abstract: The double containment is adopted in most of the 3 rd generation nuclear power plant,such as EPR, VVER, and HPR1000, of which the external containment can be used to resist the malicious impact of large commercial aircraft, and the inner containment can prevent the leakage of nuclear radiation. Aiming at better economic performance, the double containment could be optimized to single containment, which could resist aircraft impact and act as a radiation barrier, while the feasibility needs to be evaluated. In this paper, the refined finite element model of reactor building with single containment and double containment are established. By adopting the missile-target interaction analysis method, the acceleration response spectrum and the acceleration time-histories of bracket, inner floor and equipment supporting point are analyzed and compared in three impact scenarios. Based on comparison results, from the aspect of vibration response, the feasibility of double containment optimized to single containment is evaluated.