Abstract: A method for the direct determination of trace tin in polymetallic ore on a full spectrum AC/DC arc emission spectrometer was set up. Ge was used as the internal standard, K₂S₂O₇, Al₂O₃, KI, C powder were used as the buffer, and the buffer were mixed with the sample at a ratio of 1∶1 for the determination. The detection limit of this method was 0.16 μg/g, the precision was 4.43%~7.38%, and the recovery was 91.4%~109.0%.The method was used to determine the national first-level standard materials, and the result was in good agreement with the standard value. The method is simple, rapid, is suitable for a wide range of analysis and testing, and can meet the requirements of the analysis of polymetallic ore samples.