Abstract: According to the test information of a static load test on a 1∶ 3 scale specimen of a large-span half-steelconcrete ( HSC) hollow composited plate for the composited roof of a nuclear power plant，a nonlinear finite element model of the composited plate specimen was established using ANSYS finite element software． Through comparison between the load-deformation curves derived from the experimental results and the numerical simulation，it can be illustrated that the model can simulate the HSC plate accurately． The numerical simulation show that during the loading process，micro cracks appeared first on the concrete surface of the lower part of the lateral web plate of the plate． it can be concluded that by means of appropriate shear connection and anchorage length，steel plate and concrete can work together very well and the HSC plate has high capacity and ductility．