Abstract: Barite polymetallic associated ores commonly contain valuable metals such as Sr, Si, Fe, Cu, Pb and Zn in addition to the major element Ba. Rapid and accurate determination of these valuable elements is of great significance for comprehensive resource utilization. Inductively coupled plasma optical emission spectrometry (ICP-OES) has been applied to the determination of Ba, Sr, Si and Fe in barite. However, the simultaneous determination of Cu, Pb and Zn remains constrained by matrix interference and sulfate precipitation effects. In this study, X-ray diffraction (XRD) was employed to characterize the mineralogical properties of the barite polymetallic ore, providing a basis for the selection of sample decomposition method. The sample was subjected to Na₂CO₃ fusion, Na₂CO₃ solution leaching, filtration and HCl re-dissolution. Sulfate ions (SO₄²⁻) were removed by filtration, eliminating their interference with Pb and Zn determination; the filtrate was rapidly acidified for Si determination, while the precipitate was re-dissolved with HCl for the determination of Ba, Sr, Fe, Cu, Pb and Zn. The fusion conditions and instrumental parameters were optimized, and matrix-matched calibration was employed to eliminate spectral matrix effects, allowing the simultaneous determination of the above seven components by ICP-OES. The correlation coefficients of calibration curves exceeded 0.9995, and the method detection limits ranged from 0.0037% to 0.025%. The relative standard deviations (RSDs, n=7) for certified reference materials ranged from 0.11% to 4.37%, with relative errors of 0.01%–3.06%; the spiked recoveries for actual samples were 96%–104%. The proposed method achieves the simultaneous determination of major elements (Ba, Si) and trace valuable metals (Cu, Pb, Zn) through sulfate separation and is suitable for batch analysis of multiple major and trace elements in complex barite polymetallic ores.