As a shallow water bathymetry technology, the space-borne laser measurement system can cover some remote waters that are difficult to reach by airborne/shipborne systems. It has unique advantages such as high measurement accuracy, working day-and-night ect. Taking a few sparse active space-borne laser measurements as the water depth calibration points, integrating passive space-borne remote sensing images, active and passive fusion is the current frontiers and hotspots in the field of bathymetry. We first introduces the working range, physical parameters and data products of space-borne photon-counting lidar, followed by the summarization of the measurement principle and theoretical transmission models, as well as the comparison of the advantages and disadvantages of different point cloud data denoising algorithms. At last, this paper concludes the application of space-borne fusion bathymetry inversion technology in different environ-ments, combs the process of technology development, summarizes the current problems, and looks forward to the future prospect and development direction of the technology.