Disclosed are a method and system for dividing a plant organ point cloud. According to information about lamina point cloud blocks and stem point cloud blocks in a previous adjacent point cloud frame of a point cloud frame to be divided and a flatness feature of a data point of the point cloud frame to be divided, a point cloud of the point cloud frame to be divided is divided into lamina point cloud blocks and stem point cloud blocks taking the adjacent point cloud frame as a reference to divide the point cloud frame facilitates the divided organ in maintaining the consistency of time and space between adjacent point cloud frames, and improves the accuracy of plant organ division. When a new lamina point cloud block or a stem point cloud block is discovered, the point cloud in the point cloud frame before the point cloud block to be divided is redivided through tracking back when redividing, according to information about the lamina point cloud blocks and the stem point cloud blocks in the next adjacent point cloud frame, the point cloud frame to be redivided is divided and the redivision during tracking back facilitates extracting, from the point cloud frame, a new lamina point cloud block or a stem point cloud block which was not discovered in the previous division process, thereby further improving the accuracy of plant organ division.
