This study investigated the effect of dihydromyricetin on the flotation behavior of chalcopyrite and galena throught pure mineral flotation test, contact angle measurement, ultraviolet spectrophotometer and X-ray photoelectron spectroscopy analysis. At the same time, the mechanism of dihydromyricetin on the inhibition of galena was also studied. The research results indicate that the flotation index of single mineral is in good condition. When using 1.0×10-4 mol/L dihydromyricetin in the flotation test of artificial mixture, the grade and recovery rate of copper concentrate are 29.28wt% and 99.04%, respectively, and the grade and recovery rate of lead concentrate are 86.29wt% and 87.55%, respectively. The larger the contact angle on the mineral surface, the more hydrophobic and floatable of the mineral is. The contact angle measurement show that after adding dihydromyricetin, the contact angle of chalcopyrite decreases by 5.40°, while the contact angle of galena decreases by 13.78°, which significantly affects the wettability of galena surface. The adsorption capacity test results show that the galena has a higher affinity for dihydromyricetin than chalcopyrite. After treatment with dihydromyricetin, the adsorption capacity of galena on the mineral surface significantly decreases, while the adsorption capacity of chalcopyrite changes slightly. The difference in the adsorption amount of the collector further increases the floatability difference between the two. The XPS results show that the content of Pb(OH)2 increases significantly after dihydromyricetin treatment, from 11.72% to 24.73%, and the hydroxyl group of dihydromyricetin and the metal hydroxide oxidized on the surface of galena are adsorbed on the mineral surface through the interaction of Bronsted acid and alkali, which hinders the interaction between the collector and the mineral, what's more, this leads to two different flotation phenomena of chalcopyrite and galena.