Patent documents in a broad sense refer to all documents related to patents, including patent applications, authorizations, invalidation, lawsuits and technical reports. Patent application refers to the request made by an inventor or enterprise to the Patent Office for the protection of the exclusive right of invention-creation; Patent authorization means that the patent office, after examining the patent application of an inventor or enterprise, considers that it meets the conditions stipulated in the patent law and grants it a patent right; Invalidation refers to the procedure of revoking or invalidating an authorized patent; Litigation refers to the litigation documents of patent infringement, invalidation and other related cases; Technical report refers to the literature related to the research results or progress in a certain technical field. Patent literature in a broad sense is of great significance to patent retrieval, patent infringement litigation and technical research.