Abstract: Ignoring the effect of geometry nonlinear on coupling, the traditional methods of calculating transient thermo-mechanical coupling under the hypothesis of geometry nonlinear cannot reflect the heat transfer and structural deformation coupling accurately within a wide extension of temperature. Hence, a transient finite element method considering geometry nonlinear is established to solve the problem of thermo-mechanical coupling based on Galerkin and Newmark algorithm. Thereafter, the method is validated by calculating the dynamic behaviors of an orthotropic thin plate under thermal environments, and it is further applied in solving the thermo-mechanical coupling problem of a honeycomb panel of the thermal protection system on a hypersonic flight vehicle. The results indicate that the coupling term with small effect on temperature can cause vibration of temperature, speed up the convergence of structural deformation and alleviate structural vibration with the damping proportional to temperature. In addition, the hypothesis of geometry nonlinear can substantially increase the amplitude of the change of temperature, as well as the vibration velocity, and affects the structural deformation.