The invention relates to a similarity matching method of cutting tool pictures, and belongs to the technical field of information. First of all, a gray-scale map is generated; then an image including a tool portion is obtained by removing angle squares at the two sides of a tool image; then performing gradient field operation of a GVF smooth image, eliminating details with quite small noise and scales, and obtaining an image with clear tool contour; then carrying out feature point detection; performing main direction distribution on detected feature points; according to main directions of the feature points, generating feature descriptors; and obtaining the size of similarity by performing feature point matching on feature vectors in the feature point descriptors by use of an Euclidean distance formula. The method can effectively solve the problem of incapability of classifying cutting tools due to concentration of the feature points in local small details (features with quite small scales) of an object by use of a standard SIFT algorithm, completes a comparison algorithm of image similarities through GVF-Harris-SIFT, and finally realizes type classification of the cutting tools of an engineering project.