Spaceborne cloud radar is a kind of active remote sensing instrument. It can achieve all-day, all-weather continuous observations of global cloud vertical structure and cloud liquid water, ice water content. Compared to the current millimeter-wave cloud radar, terahertz cloud radar has a higher sensitivity and a shorter wavelength which is closer to the cloud droplet size. The improved sensitivity is of great significance to detect the liquid water, ice water content of clouds with much lower sensitivity of −40dBZ. In this paper, researches are carried out on the spaceborne terahertz cloud radar design of system parameters and hardware implementation. The system demonstrations of the spaceborne cloud radar are presented, giving a case of operating parameters satisfying the detection requirements. The hardware implementations are proposed based on the radar operating parameters, along with the composition and performance requirements of each hardware subsystem in detail.