Aging is a process in which the functions of multiple organs, tissues and cells of an organism decline, and diseases related to aging will gradually appear during the aging process, accompanied by changes in epigenetic mechanisms, and studies in related fields have also shown that the process of changes in epigenetic mechanisms is closely related to biological ageing. With the intensification of global aging phenomenon, anti-aging has gradually become a research direction of great interest, however, the epigenetic characterization, mechanism and quantitative analysis of the aging process still need to be studied in depth. In this paper, we review the current research progress in the field of aging and age prediction based on DNA methylation, introduce the basic principles of epigenetic clock, biological clock and DNA methylation, as well as the typical research methods and effective sample resources of the corresponding epigenetic clocks, and discuss in-depth the challenges of the research in this field as well as the trend of development, with the aim of providing comprehensive references for the researchers to facilitate the anti-aging related clinical practice and the development of large health applications.