Interleukin 10 (IL-10) is a multifunctional cytokine that can participate in the immunity of the body. It is secreted by various immune cells such as monocytes and macrophages, and plays an important role in the development of various diseases such as anti-tumor, anti-infection and immune diseases. A variety of scleractinian fish IL-10 has been clonally expressed and has also been shown to have immunomodulatory effects, and there are a number of studies on the biological activity, mechanism of action, and regulatory mechanism of IL-10 in fish. To provide a reference for the study of fish IL-10, its genetic organization, transcriptional expression, origin, evolution, biological activities and function, fish IL-10 receptor and signaling pathway are reviewed.