Mercury (Hg) isotopes, which display mass-dependent fractiona-tion and mass-independent fractionation, provide a multidimensional tracer todecipher the source of metals in mineral deposits. However, mineral ore samplesusually contain abundant interfering elements (e.g., Te) that can cause inaccurateHg isotopic analysis. Available acid digestion and combustion methods failed toremove these interfering elements, hindering the application of Hg isotopes formetallogenetic tracing. Here, we developed a new dual-stage tube furnace systememploying a Mn-containing catalyst tube to pretreat mineral ore samples. Thismethod yielded good Hg recoveries (100.5 ± 3.8%, 1SD, n = 15) and low levelsof interfering elements in sample solutions, allowing for accurate analysis of aseries of ore standard reference materials (GBW-11108v: coal; GSO-3: Cu−Agsulfide ore; GBW 07859: Au−Te sulfide ore). The new method was alsosuccessfully applied to measure the Hg isotopic composition of magmatic andhydrothermal ore deposits, which yielded a large range in Δ199Hg value (−0.19 to 0.22‰) for ore deposits formed in differentgeological settings, highlighting the future applications of this method for metallogenic tracing, especially tracing the source of metalsin mineral ore deposits.