Patent document refers to a document written in accordance with the format and content requirements stipulated in the patent laws of all countries in the world, which specifically records the specific technical scheme for applying for a patent. As a record of scientific and technological knowledge, patent literature contains rich information resources. No matter which country's patent documents are, descriptions such as patent name, patent applicant, patent classification number, patent inventor, year of invention (priority time) and abstract of patent specification must be marked on the title page of patent specification. The statistics of these standardized data items can reflect the technical activities of countries or patentees in different periods and fields and the output of intellectual property protection strategies.