The retrieval of patent legal status refers to the timeliness and regional retrieval of patents, which can be divided into: patent validity retrieval and patent regional retrieval. Patent validity retrieval refers to the retrieval of the current status of a patent or patent application, with the purpose of knowing whether the patent is valid or not. Patent regional retrieval refers to the retrieval of patents applied for by an invention in those countries and regions, with the purpose of determining the national scope of the patent application.