The writing of the National Natural Science Foundation must have a big picture, so that small peers can read it first and experienced peers can read it at last. Peer review is one of the important ways for sci-tech journals to select papers and maintain and improve academic quality. With the formation of the concept of subject classification, "peers" are divided into "big peers" and "small peers". "Small peers" are engaged in the same or similar topics as the author. In the practice of peer review, we find that the comments of "big peers" experts are often vague, while the comments of "small peers" experts are appropriate and sufficient, and the review speed is fast.