External auditing refers to sending papers to experts from other units for auditing. Some schools are under the unified guidance of degree offices, while others are under the guidance of tutors. Although the reviewer knows the source unit of the paper being reviewed, the author's name is hidden when reviewing the paper, so external review is more fair and objective than internal review (the review of the unit or the staff of our school), and the evaluation of each paper is more just and basically without personal feelings.

The contents of the external audit of the paper are mainly quality, innovation, structure, arguments, arguments, experimental design, experimental data and so on. Compared with the preliminary review and final review, the review is more content and stricter, so the review cycle is longer and the rejection rate is higher, which is a link that many authors are worried about.