External examination of papers refers to sending papers to experts from other units for review. It mainly depends on whether the quality of the paper reaches the level of periodical submission, which is a review of professional quality knowledge. External audits take a long time because they sometimes verify the data appearing in the documents. In order to test whether the experimental data and methods in the paper are scientific and whether the conclusions are in line with the development of the industry. Experts mainly review the following aspects: ① political review. Mainly to investigate foreign-related issues, religious issues, historical issues, confidentiality issues, other political issues and so on. ② Innovative review. Innovation mainly refers to the new contribution of papers to human knowledge, technology or thought. (3) Analysis of the source of the paper: The fund subject is strictly examined and approved, and the funds are sufficient, so the paper may be more innovative. ④ Analysis of the author's information: The quality of new works by recognized high-level authors may be good, because the research is inherited, and the quality of papers is positively related to the quality of authors.