There are many types of RNA modifications, and the content and functions of different types of RNA modifications are also very different. Among them, methylation modification is one of the main forms of RNA modification, accounting for about two-thirds of the total amount of RNA modification. RNA methylation modification mainly occurs at special positions such as the nitrogen atom and carbon atom on the base group, and the oxygen atom of ribose 2'OH. RNA methylation modifications that are ubiquitous in archaea, prokaryotic bacteria and eukaryotes include m6A, m6,6A, m1A, m5C, 3-methylcytosine (m3C), 7-methylguanine (m7G), Cm, Gm, m5U and Um, etc.