Humans are widely exposed to multiple metals, some of which are suspected to be hepatotoxic, and diabetes mellitus (DM) is a risk factor for chronic liver disease. This cross-sectional study aimed to explore the association of multi-metal exposure and liver function in elderly with diabetes mellitus. We enrolled 1663 subjects aged ≥ 60 years and measured the levels of 22 plasma metals and liver function parameters (total bilirubin (TBIL), alanine transaminase (ALT), and aspartate transaminase (AST). Generalized linear regression model (GLM) and Bayesian kernel machine regression (BKMR) were used to investigate the correlations of multi-metal combined exposure with liver function parameters in the elderly. Multivariate GLM results shown that plasma Fe was positively related with TBIL and plasma Ti and Sr were negatively associated with TBIL in DM elderly. Positive associations were found between Ti-AST and Sn-ALT. In BKMR model, multi-metal combined exposure showed a “U” sharp association with TBIL in overall elderly and an inverse association in DM elderly. Further analysis of the BKMR model revealed that Fe, Ti, and Sr combination exposure had interaction effect with TBIL in the overall and non-DM groups; however, no interaction effect was found in the DM elderly group. Our results suggested that combined exposure of plasma Fe, Ti, and Sr was inversely associated with TBIL in elderly with DM. Potential mechanisms of the complex metal effects on liver function in DM elderly deserve further investigation.