To monitor the space environment and its effects in the low-Earth sun-synchronous orbit of China’s FY-3 satellite, a comprehensive detection technology based on the type Ⅱ loads of the space environment monitor is proposed. In the process of ground development, various technical indicators of the space environment comprehensive detection payload have been calibrated and experimentally verified by different methods such as standard radiation source, equivalent signal source, particle accelerator and standard magnetic field. The results show that the multi-direction full-spectrum particle detection achieves an energy range of 30 keV–300 MeV, with the accuracy of ≤10%. The magnetic field detection realizes the measurement range of −65023–+65023 nT, with the accuracy of ≤0.73 nT. The potential detection realizes the measurement range of −32.4–+23.7 kV, with the sensitivity of ≤10V. The detection of radiation dose realizes the measurement range of 0–3×104 rad (Si), with the sensitivity of ≤8.3 rad (Si). Through comprehensive observation of particle radiation environment, change of in-situ magnetic field vector, radiation dose accumulation and change of satellite surface potential in satellite operation orbit, the space environment monitor provides necessary data support for space activities, satellite design, space science research and space weather early warning and prediction.