In nuclear radiation environment, the radiation protection of vehicles such as ships and tanks is crucial for nuclear safety, radiation protection, radiation damage assessment, response and decision-making. This paper does research on ships’ radiation shielding performance. Using ship materials and typical structures, neutron-photon coupling transportation method is adopted to quantitatively simulate ship’s radiation shielding performance, under neutron and γ’ simultaneous irradiation. By utilizing large-scale parallel technology, efficient simulation has been achieved for deep-penetrating problem. The simulation of radiation transportation process considers incident neutrons, γ and even secondary particles. For basic shape models such as plate, cavity with different thicknesses and materials, it simulates neutron and γ's transportation in gas and materials, monitors particles flux, dose, and energy spectrum. The radiation protection factors(RPF) for neutrons, γ rays, and both are simulated and analyzed. It studies RPF influence rules with key parameter such as plate thicknesses, incident angles. The materials researched include Fe, Al, Pb, HSLA100 steel, and the radiation sources include single energy neutron, and nuclear leaked neutron and γ spectra. These results will contribute to the analysis of vehicles’ radiation protection performance, and provide theoretical support for nuclear radiation effect assessment, emergency response, etc.