Abstract: Based on the engineering practice of nuclear island building structural design, the paper studied the failure modes of concrete barrier as well as the structural design method under impact load. Various failure modes for reinforced concrete were introduced under the impact load. In addition, the empirical formulation and typical calculation example recommended by the civil engineering design codes for nuclear power plants at home and abroad were presented to evaluate the local effect for the concrete. Aiming at the analysis of the overall effect of reinforced concrete walls and slabs under impact load, the paper introduced the concentrated mass model for single degree freedom system commonly used in engineering practice, which is simple and mature. For the concrete barrier structure with large load and complex support relation, the elasto-plastic time-history analysis could be used to study the bearing capacity and failure mode of the concrete barrier structure more accurately. Finally, the process and method of numerical simulation analysis were introduced with the example of drop analysis for the head assembly of the pressure vessel in the reactor building.