Abstract: According to the feature that images of stored-grain pests have no obvious lines，a new rectification algorithm based on Hotelling transform about the area and edge of pests was presented. Firstly, the minimum exterior rectangle was gotten through automatic searching, and image binarization was made with adaptive threshold. Then the coordinates of the region and edge of pests within the rectangle were drawn out, and eigenvectors of covariance matrix were calculated and thus the Hotelling transform matrix was constituted. The images of original slantwise pests were rectified by the matrix of Hotelling Transform. Experimental results show that the new method can rectify images of the stored-grain pests efficiently and accurately with high noise endurance and application adaptability.