In this study, the Keyence VHX-5000 ultra-depth three-dimensional spectrophotometirc system, the X-rite VS450 colorimeter and other related instruments were used to conduct surface observations and chromaticity monitoring on samples of Xuan Wu mural painting unearthed from the Tang Dynasty tomb of Han Xiu. The study found that the yellow pigment in the mural is a mixture of vanadium-lead ore and lead. The lead carbonate produced by the oxidation of lead in the tomb was further oxidized to lead oxide in the laboratory environment. With regard to chromaticity, research shows that the ΔE value, which shows the difference in chromaticity before and after reinforcement, is around 4.33, which is within acceptable standards.