An fluid-structural-thermal integrated algorithm was presented based on detailed discussion about the deficiency in domestic and foreign study on algorithm of fluid-structural-thermal integrated. A unified integral equation system was developed as the control equation for physical process of aero-heating and structural heat transfer. The whole physical field was discretized by using an up-wind finite volume method. The corresponding algorithm were given to work out the value of the temperature

the temperature gradient and the heat transfer coefficient on the boundary between fluid and structure. In terms of time step

a multi-step Runge-Kutta iteration scheme was used in steady states while a dual-time step method was adopted in unsteady states. Numerical simulation of the aero-heating and structural heat transfer problem on a two-dimensional circular tube model was performed. Results show that the 2s stagnation surface temperature is 390K. Compared with other papers

the maximum absolute error is 3.1K. The steady state stagnation surface temperature is 647K.