Due to the advantages of high speed, low altitude and strong maneuverability, it is difficult to effectively detect near space hypersonic vehicles by the early warning and detection system consisted of land/sea-based radars and high orbit infrared satellites in whole process. Therefore, according to the technical characteristics of hypersonic vehicles, the detection capability and global coverage of low-orbit infrared satellites are researched. Firstly, based on the aerodynamic shape of HTV-2-like lift body, the surface temperature distribution of the aircraft under typical operating parameters is simulated. Then, the detection model of low-orbit infrared satellite is established. Combined with the typical parameters of infrared detector, the relationship among signal-to-noise ratio of detector, observation angle, and working band at different orbital altitudes is given, and the effective detection half cone angles of infrared satellites at orbital altitudes of 550 km and 1600 km are obtained. Finally, the configuration and main parameters of low-orbit infrared satellite constellation with global detection capability are given.