Postmenopausal women undergo significant changes in endogenous hormones, which lead to reduced bone mineral density (BMD) and alterations in body composition. However, the relationship between body composition and cognitive function in this demographic has not yet been explored. This study aims to examine this relationship in postmenopausal women with osteoporosis.This survey will involve 120 postmenopausal women with osteoporosis. Dual-energy X-ray absorptiometry (DXA) will be used to assess L1-L4 BMD, fat mass (FM), trunk fat mass (TFM), fat-free mass (FFM), and appendicular skeletal muscle mass (ASMM). The relationship between body composition and cognitive function will be analyzed using t-tests and multiple linear regression.Our findings suggest that in postmenopausal women with osteoporosis, cognitive function (MMSE score) is positively correlated with body composition indicators such as FM and BMD, and positively correlated with educational level, but negatively correlated with age. FM plays a significant role in influencing cognitive function and is a crucial indicator of body composition in postmenopausal women with osteoporosis.