Abstract: A dynamic coupling model of wind-train-bridge system is established, while taking into account the geometric nonlinearity of long-span suspension bridge. The initial internal forces and the gravity-induced sag deflection of the main cables are considered when establishing the finite element model. The large displacement is calculated by adding the geometric stiffness in the dynamic equilibrium differential equations. The linear and nonlinear dynamic responses of the Wufengshan suspension bridge with a 1120 m main span are calculated using the self-written computer program. The results show that the large displacement nonlinearity of the structure does not influence the intendancy of bridge displacement and acceleration histories, but reduces the maximum values of the responses. The geometric nonlinearity influence on the bridge accelerations is more obvious than that on the displacements.