Abstract: By measuringthe static aerodynamic coefficients of the three components of forces through section model test and taking into account the components of the displacement-dependent wind load and geometric nonlinearity, the authors of this paper propose a nonlinear finite elementmethod (FEM) to assess the static stabilityof catwalk of a suspension bridgewith amiddle span of 960 m. Meanwhile, a full model tunnel-test of the catwalk is also performed. By comparing the displacements measured in the full model tunnel-test with the results obtained from the nonlinear FEM, it is shown that the nonlinear FEM can efficiently assess the stability of catwalks of suspension bridges as the full model test.