The thermal equation of a deployable truss parabolic antenna was derived by finite element method, the convergence criteria of real root and thermal steady state root about thermal equation were built according to the features of space deployable truss antenna. The thermal dynamic forces were simulated by model nodes temperature. Typical model node displacement and root mean square of antenna induced by thermal dynamic forces were discussed. The results show that thermally induced vibration occurs at the beginning of thermal dynamic forces great change and stops by damping and right structure type. The dynamic response is mainly structural basic frequency. At the same time, value of root mean square of antenna induced by thermal drastically changes at the beginning.