The invention belongs to the technical field of the laser radar remote sensing technology and particularly provides a method for extracting a vegetation canopy aggregation degree index based on the three-dimensional laser point cloud. According to the technical scheme of the invention, the remote sensing technology is adopted to obtain the three-dimensional point cloud data of a vegetation quadrat canopy. Through the processes of constructing a three-dimensional volume element model, converting a coordinate system, calculating a canopy clearance rate and the like, a method for extracting the vegetation canopy aggregation degree index based on ground high-resolution laser point cloud data is established. Based on the method, the vegetation canopy aggregation degree index can be quickly and accurately extracted, and the data acquisition is simple and convenient. Meanwhile, the process is not influenced by the lighting condition during observation. During the study, the pixel scale factor of satellite remote sensing data or products is not taken into consideration. Moreover, no adverse effect on vegetation structure and radiation characteristics exists. At the same time, the three-dimensional structural features of a vegetation sample can be permanently recorded. The method is simple, convenient and efficient, and does not have side effects on vegetation. The calculated amount is greatly reduced compared with the prior art.