The invention discloses a sorting method for guiding a mechanical arm to grab materials with different poses based on a ConvPoint model, three-dimensional point cloud data of the materials is obtained through a 3D structured light camera, the three-dimensional point cloud data is combined with the ConvPoint model for material sorting, the method is not affected by the initial poses and appearances of the materials, various grabbing targets are achieved, and the system robustness is higher. Compared with an existing deep learning method, the method has the advantages that grabbing sampling is improved through PCA, the material grabbing accuracy is obviously improved, in addition, the point cloud in the network input clamp is evaluated instead of the point cloud of the whole object, the learning and reasoning time is shortened, and the material sorting efficiency is greatly improved. Besides, in the ConvPoint model training stage, the point cloud data of different types of complex structure materials are collected in real time to serve as a training set, the method does not depend on a data set of simple objects of an online open source, complex objects of different poses are grabbed, and the intelligent level and the automation level of a sorting system are improved.