The organisation of spaces and paths is the key to determining the spatial structure of landscape architecture, and is also the main content expressed in the bubble diagram and structural schematic at the early stage of design by designers. The purpose of this paper is to explain the landscape spatial structure from the origin of design, using social network analysis and spatial syntax comprehensively, and to propose a construction and quantitative research method suitable for landscape spatial structure and path structure. This study mainly addresses the following problems: 1) how to extract spatial units and path relationships from complex landscapes and establish a structural model based on 3D spatial data; 2) how to analyse landscape spatial structure characteristics systematically and quantitatively; 3) how spatial organisation and path organisation are associated to influence landscape structure and spatial characteristics. Taking the Lovers Park as an example, the study verifies the feasibility of the method through the processes of 3D point cloud data acquisition, spatial units’ extraction, construction of spatial structure network and path structure network, visualisation of the structure model, and calculation of quantitative indexes. The results show that the method can achieve accurate, effective, and systematic analysis and visualisation of the landscape spatial structure, and that the spatial layout is closely connected with the road network organisation, and both have an important influence on the landscape structure.