Abstract: We built a labyrinth heat transfer wind tunnel. Detailed experimental results on the flow field reveal the velocities and vortices distribution in the cavity of labyrinth seal and lo-cal heat transfer coefficient distribution on the roof of labyrinth. Analyzing the results obtained at different Reynolds number and T/C, We found the influence on the velocity and pressure distribution in cavity of labyrinth and the influence of different Reynolds number and T/C on the heat transfer coefficient on the roof of labyrinth seal.