In order to study the dynamic response of bulkhead plates with different boundary conditions under explosive load, the general finite element software Abaqus is used to establish the complete cabin structure model and several bulkhead plate models. The decoupling method is used to obtain the pressure time history acting on the bulkheads in the cabin when exploding in the cabin, the pressure load is applied to the bulkhead plates in the cabin to obtain its dynamic response, and the calculation results of various models are compared. The results show that：for the bulkhead plate model, it is the most reasonable boundary condition to release three rotational freedom constraints on the four sides of bulkhead plate and retain three displacement freedom constraints; the ratio of length to width of bulkhead plate is a great influence on the central displacement of bulkhead plate; it is a little influence on the central displacement of bulkhead plate to release the rotational freedom constraints on the four sides of bulkhead plate, and the rotational freedom constraint is an obvious influence on the bulkhead plate deformation fitting function. The obtained numerical calculation results can provide reference for the relevant research.