Osteoporosis is emerging as a growing public health concern worldwide due to the aging population, and metal exposure is widely recognized as a risk factor for human health. However, studies on the relationship between metal exposure and bone health yield inconsistent results. Limited epidemiological research exists on the associations of metal mixtures with osteopenia and osteoporosis, particularly among ethnic minorities in China. We conducted a study on 9206 ethnic Chinese (Dong and Miao) aged 30–79 years using data from the Chinese Multi-Ethnic Cohort Study (CMCS) baseline survey database. We utilized inductively coupled plasma mass spectrometry (ICP-MS) to measure the concentrations of 11 metals in urine and quantitative ultrasound to measure bone mineral density (BMD). Multivariate logistic regression model, Quantile g-computation and Principal component analysis were used to explore the correlation between single-metal exposure and metal mixture exposure with osteopenia and osteoporosis. In the single-metal exposure model, urinary concentrations of As, Cd, Cr, Fe, Hg and Mn were positively associated with the risk of osteopenia. Conversely, urinary Co and Zn were negatively associated with the risk of osteopenia. Urinary As, Cd, Cr and Mn were positively associated with the risk of osteoporosis, while urinary V was negatively associated with the risk of osteoporosis. In addition, Quantile g-comptation showed that exposure to metal mixtures was positively associated with osteopenia and osteoporosis. Principal component analysis identified principal component 1, characterized by Fe and Mn, and principal component 3, characterized by Hg and Cd, as positively associated with osteopenia and osteoporosis. These findings suggest that the co-exposure of polymetals affects the occurrence and development of osteoporosis, warranting further investigation into the complex mechanisms involved.