Abstract: The space environments and their effects in the low Earth orbit (LEO) pose a serious threat to the LEO spacecraft, therefore, it is necessary to monitor the related environments and their effects. This paper proposes an integrated design of the environmental monitoring device onboard the LEO spacecraft. The design is explained from the aspects of the electronic circuit integration, the corresponding payload design, and the structural optimization, in view of its capability of monitoring the electron & proton irradiation, the atomic oxygen, the local temperature, the surface potential, the total dosage, and the contamination. The instantaneous parameters (flux, dose rate, contamination deposition rate) as well as the cumulative parameters (fluence, total dosage, total contamination level) can be monitored simultaneously.