The invention relates to the technical field of an H-dimensional image segmentation algorithm, in particular to a litchi mechanical damage judgment method. The method comprises the steps of 101, inputting litchi image samples, and by utilizing the H-dimensional image segmentation algorithm, obtaining litchi region segmentation image data; 102, according to a principal component analysis (PCA) algorithm, processing the litchi region segmentation image data to obtain principal component eigenvectors; and 103, according to a support vector machine (SVM) algorithm, inputting the principal component eigenvectors, outputting litchi category samples, and building a litchi mechanical damage classification model. The litchi mechanical damage PCA-SVM classification model is built by utilizing the H-dimensional image segmentation algorithm, the PCA algorithm and a SVM, and litchi sample images can be processed, so that whether litchis are mechanically damaged or not can be judged.