In order to suppress the contribution of the last-stage turbine rotor to the infrared (IR) radiation in backward of the exhaust system, the fully shielded guiding strut (FSGS) was designed. IR signatures of the baseline axisymmetric exhaust system and the exhaust system with FSGS under different cooling conditions were obtained by experiments. The results indicated that the wall temperature of the FSGS was lower than that of the last-stage turbine rotor. However, the wall temperatures of the heat shield and nozzle of the exhaust system with the FSGS increased. FSGS had an outstanding effect on suppressing the IR radiation of the exhaust system within the directions of 0° ~ 10°, and its IR radiation intensity was 13.9% lower than that of the baseline axisymmetric exhaust system at 0° detection angle. The application of film cooling on the FSGS can further reduce the IR radiation of the exhaust system in those directions mentioned above. Under the blowing ratios (BR) of 0.5, 0.7 and 0.9, the IR radiation intensity of the exhaust system at 0° detection angle was weakened by 18.1%, 25.8% and 34.5%, respectively. Therefore, the FSGS with film cooling is a very effective way to suppress the IR contribution of the last-stage turbine to the exhaust system.