According to the false alarm problem in infrared early warning satellite, the space radiation environment of the geosynchronous orbit infrared early warning satellite was studied. Based on the analysis of satellite′s background radiation characteristics in the detection spectrum and as a benchmark, the radiation sources in space environment that may cause false alarms of infrared early warning satellite were analyzed. The radiation characteristics of various sources in the 2.63-2.83 μm short-wave detection spectrum and the 4.18-4.50 μm medium-wave detection spectrum of infrared early warning satellite were discussed and calculated individually. The results show that the irradiance of direct solar radiation on the satellite detector is much larger than the background radiation intensity of the satellite, so evasive measures should be taken. The main false alarm sources of infrared early warning satellite are lunar radiation and low-Earth orbit spacecraft radiation. The influence of lunar radiation is mainly due to the focusing factor of lens. The influence of near-Earth orbit spacecraft radiation occurs in the mid-wave detection spectrum of infrared early warning satellite. The research results can provide reference for the study of corresponding background suppression and false alarm sources identification technology.