The invention discloses a crown appearance extract method based on shape analysis. The data treatment of the invention is characterized in that a laser scanner carries out single-sweep on a whole plant to obtain the single-sweep point cloud data of the plant; firstly, a root node is found from the point cloud data, and then the point cloud data is divided into branch point cloud and leaf point cloud by a shortest distance method; a corresponding skeleton is extracted from the branch point cloud, and the skeleton is divided into a plurality of parts according to the branching characteristics of a tree, and classified branch skeletons are utilized to classify the leaf point cloud; Delaunay triangulation is carried out on each classified leaf point cloud to obtain a tetrahedron and a triangular patch; the triangular patch is divided into three classes, such as exterior, interior, boundary and the like, wherein the triangular patch located on the boundary forms a sealed body which is used for representing the shape of the classified leaf point cloud; and the shape integration of each class of the leaf point cloud represents the shape of the whole crown.