Polycystic ovary syndrome(PCOS) is a clinically common heterogeneous disease characterized by reproductive disorders and metabolic abnormalities.Endoplasmic reticulum stress refers to an adaptive response of eukaryotic cells due to various factors leading to the misfolding and/or aggregation of proteins.By reviewing ancient literature on the theory of spleen governing transportation and transformation，it was found that the function of the spleen in transporting and transforming water and grains，dispersing nutriment throughout the body is similar to the important role of the endoplasmic reticulum in cells in modern medicine.Both are involved in tasks such as protein folding and calcium storage to ensure normal cellular physiological functions.If the spleen loses its transportation and transformation function，phlegm-damp obstruction is the core pathogenesis of this disease.Modern scientific research believes that endoplasmic reticulum stress can better explain the pathogenesis of spleen dysfunction，which is consistent with the understanding of pathogenesis in traditional Chinese medicine.Given the similarities between the pathogenesis of PCOS and endoplasmic reticulum stress，both associated with inflammation，oxidative stress，excessive androgen，and abnormal insulin synthesis and secretion，endoplasmic reticulum stress may play an important role in the PCOS progression.The application of spleen-governing transportation and transformation principle can delay the occurrence of endoplasmic reticulum stress，and also can effectively alleviate the related characteristics related to PCOS，such as obesity and compensatory increase in insulin.Therefore，alleviating endoplasmic reticulum stress is expected to become a new idea for the treatment of PCOS.Nourishing and regulating the spleen，and supplementing spleen yang，serve as the primary methods for treating this condition.Adjusting endoplasmic reticulum stress from the perspective of restoring spleen function offers a different therapeutic angle to improve clinical symptoms associated with PCOS.