Abstract: A method for detecting the similarity of the patent documents based on a new kernel function Luke kernel comprises: dividing a patent document into five elements, i.e. patent title, abstract, claims, description, and main classification, constructing a new kernel function Luke kernel, calculating the similarity of the first four elements of two patent documents by using the Luke kernel, calculating the similarity between the main classifications of the two patent documents by means of character string matching, and then performing a weighted summation of the similarities of the five elements of the two patent documents to obtain an overall similarity of the patent documents. The method further improves the precision and recall in detecting the similarity of the patent documents, and can be applied to detection for the similarity of the patent documents.