The neuro-endocrine-immune (NEI) network is a key regulatory network that maintains organismal homeostasis and participates in stress responses. Its function depends on the dynamic coupling among the nervous, endocrine, and immune systems. Astrocytes, as abundant and functionally diverse glial cells in the central nervous system, are increasingly recognized as important participants in the NEI network. Growing evidence indicates that astrocytes do not merely provide structural support in the traditional sense, but also exhibit marked regional heterogeneity and functional diversity. Through broad sensing of neural, endocrine, and immune signals, gliotransmitter release, metabolic regulation, extracellular vesicle-mediated communication, and interactions with neurons, glial cells, the glymphatic system, and endocrine axes, astrocytes actively participate in the integration of neural activity, the regulation of endocrine homeostasis, and immune responses. Under physiological conditions, astrocytes contribute to the dynamic balance of the NEI network by integrating multisource signals derived from neurons, endocrine factors, and immune molecules. Under pathological conditions, such as inflammation, ischemia, and neurodegenerative diseases, the phenotype and function of astrocytes undergo substantial remodeling, thereby contributing to NEI network dysregulation and disease progression. In this structured narrative review, literature published between 2016 and 2026 was retrieved from the PubMed and Web of Science databases using “astrocytes,” “nervous,” “endocrine,” and “immune” as search terms. It summarizes the structural and functional basis of astrocytes and the mechanisms by which they regulate the NEI network, with the aim of systematically elucidating the physiological and pathological significance of astrocytes in NEI network integration and providing a theoretical basis for mechanistic studies and targeted intervention strategies for related diseases.