The space-borne laser detection system has the capability to detect the vertical profile of clouds and aerosols. Existing payloads, such as the Caliop radar on the US Calipso satellite, the multi-beam LiDAR on the domestic "Goumang" satellite, and the atmospheric detection lLiDAR on air pollution monitoring satellites, are limited to single-beam cloud-aerosol detection with a narrow detection area. A proposed solution is a multi-beam cloud-aerosol detection LiDAR system that operates in a satellite orbit of 800 km and utilizes a multi-beam detection system to extend radar coverage to 30 km. The central beam employs dual-wavelength polarization detection for obtaining vertical profiles and particle species of atmospheric aerosols and clouds, while the edge beam uses single-wavelength detection for cloud profiling. This approach significantly improves data acquisition efficiency through simulation-based verification of dynamic range and high sensitivity single photon detections which reduce laser energy requirements, as well as radar weight and power consumption.Finally, through simulation, the detection effect of space-borne multi-beam cloud-aerosol detection radar on typical clouds and aerosols is verified.