As an advanced quantitative technology for cells, flow cytometry, which can make multi-paramter quantitative analysis and sorting of individual cells or biological particles, has been widely used in immunology, oncology, hematology and other fields of medical research and clinical diagnosis in recent years.It can quantitatively detect the expression levels of cytokines and the distribution characteristics of cell subsets in the intraocular fluid.Compared with traditional enzyme-linked immunosorbent assay, cell morphology and immunohistochemistry, it has the advantages of simple operation, smaller sample size, higher sensitivity and higher throughput.Flow cytometry has been widely used in the detection and subgroup analysis of cytokines related to eye diseases, such as intraocular angiogenesis, intraocular lymphoma, retinopathy, cataract, uveitis, sarcoidotic uveitis, infectious intraocular inflammation, etc.Flow cytometry plays an increasingly important role in the pathogenesis research and targeted therapy of eye diseases.In this article, the application of flow cytometry in the examination of cytokines and cytology in ocular fluid for ocular diseases were reviewed.