Point cloud data calculation method, device and system for large-range data splicing

The invention discloses a point cloud data calculation method, device and system for large-range data splicing, and the method comprises the following steps: obtaining an image of a to-be-scanned object on an objective table, determining a to-be-scanned area according to the image, and calculating the position data of the to-be-scanned area on the objective table; calculating the number of scanning times according to the position data and the length of the scanning line, and controlling a three-dimensional laser scanning device to start scanning; acquiring a scanning image, and calculating aninitial position and an end position of an effective interval in the scanning image and point cloud data in the scanning image; controlling the three-dimensional laser scanning device to continue to scan the next scanned image by taking the end position of the effective interval in the previous scanned image as a scanning starting point, and calculating the initial position and the end position ofthe effective interval of