Aerosols can alter the radiation balance of the Earth's atmosphere or affect the formation of clouds as condensation nuclei, thereby affecting the global atmosphere. Aerosol optical parameters can be used to investigate this effect. Spaceborne LiDAR systems are commonly used to obtain global aerosol optical parameters. In August 2022, China successfully launched the terrestrial ecosystem carbon inventory satellite (TECIS). The main payload of the satellite is a spaceborne multibeam LiDAR, which can observe aerosol optical parameters on a global scale. This system currently requires the comparative validation of observation results. Based on the Fernald forward-integration method, we retrieve the aerosol backscatter coefficient and depolarization ratio. Data from the micro pulse LiDAR network (MPLNET), cloud aerosol LiDAR, and infrared pathfinder satellite observation (CALIPSO) are used to compare the retrieval results of the algorithm. The results show that the aerosol optical parameters retrieved by the multibeam LiDAR are highly consistent with the data and that the R² obtained from correlation analysis is approximately 0.8. This study preliminarily verifies the observation ability of the spaceborne multibeam LiDAR system for atmospheric aerosols in the TECIS.