Gao Xinmin wrote in the 3rd issue 2022 of the Journal of Central China Normal University (Humanities and Social Sciences Edition) that in the past, ontology only focused on the ways in which synchronic things existed when it came to the question of existence. With the development in personal identity studies and the penetration of scientific achievements like relativity into the study of space-time and existential philosophy, a new research field —persistence, which has both the nature of pure ontology and the philosophical interest of personal identity, has emerged. The new tendency is to explain the personal identity across time in terms of persistence. The related research not only expands and deepens the field of personal identity philosophy, but also shows us a field different from the traditional ontology — the diachronic space-time and persistence of its subject. In order to take a step further, we should do a lot of methodological exploration in addition to further research on ontology, epistemology, logic and philosophy of personal identity.