Abstract: The development of point cloud technology provides an essential opportunity for the accurate quantification and precise design of landscape space. In this research, the landscape space density (LSD) index, typically estimated on the basis of field research and experience in previous researches, is selected to optimize the quantification method adopted by using point cloud and other digital technologies. Firstly, based on the point cloud model generated by unmanned aerial vehicle tilt photography and ground-based radar scanning, this research figures out the three-dimensional morphology and overall space density of landscape elements through point cloud voxelization. Then, it visualizes the three-dimensional distribution of space density by Grasshopper. Finally, it takes the landscape space around Meian building in Southeast University as an example to explore the practical application of the quantification method. Research results shows that the proposed method has outstanding advantages in such aspects as the efficiency of data collection and processing, accuracy of calculation and readability of results, and may thus help to provide targeted optimization strategies for landscape design in a more intuitive and accurate way.