Platinum group metals (PGM), including ruthenium (Ru), rhodium (Rh), and palladium (Pd) are enriched in high-level liquid waste (HLLW) during the reprocessing of spent nuclear fuels. Vitrification is currently the only practical technology to immobilize HLLW. However, the high density and low solubility of PGM in glass cause them to settle down during vitrification process, resulting in the increased viscosity and conductivity of the glass melt at the bottom of the melter. This would potentially lead to concerned issues such as blockages in the discharge port and damage of electrodes. Therefore, understanding the deposition of PGM during vitrification is quite crucial in the management of HLLW. However, few research focused on the deposition process and the spatial distribution of PGM particles in glass melts. Thus, this work took Ru as the representative of PGM and investigated spatial distribution of Ru precipitates in glass melts.