Abstract: Normally, ocular surface microbiota coexists peacefully with human body, which plays an important role in the defense system of the ocular surface system and the immune regulation of the body. When the body state changes or the immune function is abnormal, the balance of mutualism may be broken, and the diversity and composition of ocular surface bacteria may change, thus affecting ocular surface homeostasis and immune function, leading to the occurrence of eye diseases. Current studies have found that ocular surface bacterial imbalance is closely related to ocular surface and ocular diseases. However, although microbiota exists on the ocular surface, its immune mechanism and action path remain to be further explored. This paper focuses on the current research progress on chronic systemic diseases and ocular microbiome, in order to further expand the research scope on ocular microbiome and associated diseases, and open new ideas for the study of ocular microbiome.