The stable performance of the orthotropic bridge deck with simply supported, made from steel-polyurethane sandwich plate, was studied by means of experiments and the numerical calculation method. The impact of several parameter changes of the bridge deck on the first four order buckling modes was analyzed through the calculation of elastic stability, and the impact of material nonlinearity and geometric nonlinearity of structure on the critical load was also analyzed. The results have shown that, when sandwich bridge deck is in a state of compression, the influence degree of the wheel effect on the top and bottom steel plate stress will be quite different, and that, among the three parameters, i.e. the core layer thickness, the longitudinal stiffener spacing and steel plate thickness, the first two parameters have a greater influence on the stability of the bridge deck. When designing the orthotropic sandwich bridge deck, it is recommended to set a reasonable thickness of sandwich plate at first, then to choose the longitudinal stiffener spacing by trying to calculation in order to reduce the workload.