Objective  To investigate the effects of exercise on bone strength, body composition, sex hormones and their relationship in postmenopausal women of Han nationality in Lanzhou.    Methods  From Jan. 2018 to Jun. 2019, 233 cases postmenopausal women of Han nationality in Lanzhou (110 cases in exercise group and 123 cases in non exercise group) were selected by stratified random sampling method , whose bone strength, body composition indexes and sex hormone were measured by ultrasonic bone mineral density meter, body composition analyzer and electrochemiluminescence automatic immune analyzer, respectively.    Results  There were lower body weight, body mass index and fat tissue composition of postmenopausal women of Lanzhou Han nationality (P<0.05), and there was higher bone strength, estradiol and muscle tissue composition in the exercise group (P<0.01). The prevalence of osteoporosis and obesity was lower in the exercise group (P<0.01). Pearson correlation analysis showed that estradiol and muscle tissue composition were positively correlated with the bone strength (P<0.05), and it was negatively correlated with fat tissue composition in postmenopausal women (P<0.01). Logistic regression analysis showed that limb muscle mass and estradiol were protective factors for bone, and visceral fat content was the risk factor of bone abnormality in postmenopausal non-exercise women. Estrogen was the protective factor of bone in postmenopausal exercise women.    Conclusion  The bone strength of postmenopausal women is determined by muscle and fat tissue, and the relationship between the both is affected by exercise. Exercise could effectively prevent and control osteoporosis in postmenopausal women of Lanzhou Han nationality by promoting estrogen production, increasing limb muscle and reducing visceral fat mass.