Dulan, in Qinghai province is located on the South Route of the ancient Silk Road. A large number of Sui and Tang Dynasty silver and gold ornaments were excavated from the Tubo tombs of Dulan. Among these ornaments, one Sogdian silver belt coated with a gold alloy characterized by ornamentation with a defined figure and roundels is special because the figure has the features of a Sogdian person. The belt is of great significance for the study of Eastern and Western cultural exchanges. But the gold and silver pieces were seriously corroded and in serious need of protection treatment and scientific investigation. The object was analyzed using scanning electron microscopy and Xray diffraction. The results showed that the ornament has a silver body coated with a goldsilver alloy. The silver body heavily eroded to silver oxide, which may be due to the high salt environment. The results provided theoretical support to the study and conservation of relics from Tubo tombs.