This study investigated the heavy metals in river sediments from the nonferrous metal mining area of the Yiluo River. Analysis of the geochemical characteristics of heavy metals in sediments revealed the ecological risk differentiation patterns and multi-source driving mechanisms. Based on the spatial pattern of mineral development, thirty-five sediment samples along the main stream and at the confluences of major tributaries were collected, and the content of eight heavy metals (As, Hg, Cr, Cd, Cu, Zn, Pb, and Ni) in sediments was analyzed. The geo-accumulation index, potential ecological risk index, and the absolute principal component scores-multiple linear regression (APCS-MLR) were combined to constructed the three-dimensional analytical framework of "enrichment characteristics-risk level-source contribution". The results show that: (1) Cd and Pb exhibited the most significant enrichment, with average contents 10.17 and 4.78 times the regional background values, respectively. Their spatial distribution showed a gradient decreasing from the mining areas to the downstream along the river. (2) The geo-accumulation index classification indicated that Cd was moderately to heavily enriched, while Pb and Hg were slightly enriched. (3) The ecological risks showed three-level differentiation: Cd posed an extremely high risk, Hg posed a high risk, and Pb posed a moderate risk. (4) Source apportionment identified three major contributing sources: natural background source, industrial and agricultural source, and mining activity source. A novel "element cluster-pollution source-risk level" three-dimensional matrix model was developed, categorizing Cr-Ni as natural source (low risk), Cd-Zn-Pb-Cu as mining source (high risk), and Hg-As as industrial and agricultural source (moderate risk). This model provides key data support for the simulation of heavy metal pollution migration at the basin scale, ecological risk early warning, and the research and development of targeted control technologies, offering significant practical value for the implementation of ecological conservation and high-quality development strategies in the Yellow River Basin.