With the HTV-2-like hypersonic gliding aircrafts as the research objects, their infrared radiation characteristics are simulated. With the overall consideration of the direction and spectral characteristics of the target, the background and the transmission process, the infrared detection capabilities of the ground-based platform, the floating machine and the space-based satellite to the HTV-2-like hypersonic aircrafts are systematically analyzed, and the maximum detection distances for different detection platforms and detection wave bands are obtained. The study results show that the observation direction has a great influence on the infrared radiation intensity of targets, and the maximum detection distance increases with the decrease of the detector sensitivity. The detection distance in the medium-wave bands (3.7-4.8, 3.0-5.0 μm) is longer than that in long-wave bands (7.7-9.5 μm, 8.0-12.0 μm).