Abstract: Breast cancer is a kind of hormone-dependent tumor. Its occurrence and development are closely related to the expression of estrogen receptor. Estrogen regulates various physiological processes such as cell growth, reproduction, development and differentiation. The combination of estrogen receptor and estrogen can produce a series of biological effects by activating related pathways. This article reviews the structural characteristics of estrogen receptors, their correlation with breast cancer and signal transduction pathways as well as estrogen receptor modulators and estrogen receptor antagonist, so as to provide a theoretical basis for the study of the role of estrogen receptors in breast cancer development and related molecular mechanisms, and provide ideas for the design of novel drug candidates.