External audit is the second link of periodical review, also called review, and it is also the most critical link in periodical review. The pass rate is naturally strictly controlled. It can be said that the pass rate of external review is the lowest in all links of periodical review, and the rejection rate is relatively high, while other preliminary and final reviews are relatively easy to pass.

It is slightly more difficult to pass the external review, because the external review is conducted by experts outside the journal, who are not insiders of the magazine, and the review is more objective and fair. External review is the key review of the core content of the article, which requires external review experts to reach an agreement on the article. There are usually three or four experts in the external review. If one expert disagrees with the article, the external review will not pass smoothly and the article will be retried, so it is still difficult to pass the external review.

There is no need to have too much psychological pressure on external audit. Because the external audit is mainly aimed at the professional content of the article, it is not a problem to pass the external audit as long as the professional content, arguments, data, models and other related documents in the article are well grasped and as long as these professional contents are scientific, reasonable and rigorous.