Abstract: The design of membrane structures is highly dependent on numerical calculations, and a accurate material model is the primary premise. Based on the theory of nonlinear continuum mechanics, a hyperelastic constitutive model of architectural Polytetrafluoroethylene (PTFE) coated fabric is proposed. The model decomposes the total strain energy into the part reflecting the isotropic response of the matrix and the part reflecting the anisotropic response of the fiber. Among them, the latter is composed of tensile strain energy of warp and fill yarns and strain energy due to the interaction between yarns. Based on this, the general expression of the constitutive model under biaxial tension is derived, and the solving method of the model parameters is given. The numerical model is established on the ABAQUS finite element software platform, and the nonlinear behavior of the coated fabric under biaxial tension is predicted. The results show that the model can clarify the contribution of each component material in the coated fabric to resist external load from the perspective of strain energy, predict the mechanical behavior of coated fabric in biaxial tension, and effectively represent the mechanical characteristics of large deformation, anisotropy, nonlinearity and stress ratio dependence.