The invention provides a method for manufacturing a building 
digital line map based on vehicle-mounted 
laser radar point cloud. The method comprises steps of 1: initializing original vehicle-mounted 
laser radar point cloud data and arranging all 
laser foot points as to-be-distinguished points; 2: identifying building vertical faces; 3: extracting building vertical face profiles; 4: correcting the building vertical face profiles where vertical or parallel relations exist; and 5: outputting a building 
digital line map. According to the invention, scattered 
point cloud data is organized into a space 
data structure via a 
point cloud segmentation method, wherein the space 
data structure is easy to understand by human beings, obeys natural laws and is provided with the topology relation. A building vertical 
face detection and extraction method based on prior knowledge is suitable for vehicle-amounted laser 
radar data with disordered point 
cloud data and complex distribution of region scene targets. By use of normal vector quantity of fitting panels of the building vertical faces, vertical and parallel topology relations of the building vertical faces are corrected, so precision of topology relations among the building vertical faces is effectively improved.