The heat convection was the main heat exchange in the autoclave by which composite pressure vessel was cured. To determine the heat convection coefficient, the combination of theoretical calculation and temperature test is absolutely necessary. In the theoretical calculation, the determination of the heat convection coefficient is considered as an inversion problem of thermal conduction. By adjusting convection coefficient value in the finite element calculation, optimization method was employed to obtain a good agreement between calculated temperature and measured temperature. In the temperature test, the metallic liner of pressure vessel was used as test component to record temperature data which was compared with the calculated temperature. The results present the equivalent thermal boundary condition for the simulation of curing process of pressure vessel.