Abstract: Objective To clarify the adsorption behavior of the reagent on different crystal planes of lepidolite and the mechanism of flotation differences, Method three particle sizes of lepidolite, namely -75+38 μm, -38+23 μm, and -23 μm, were taken as the research objects. Through molecular simulation calculations, the relationship between the flotation behavior of lepidolite and crystal anisotropy was studied. Result Single mineral flotation tests showed that the recovery of coarse-grained lepidolite was higher than that of fine-grained lepidolite in the dodecylamine system. XRD analysis showed a higher proportion of basal plane (001) in the coarse-grained lepidolite and an increased proportion of end plane (hk0) content in the fine-grained minerals. The results of contact angle measurements, zeta potential analysis, atomic force microscopy tests, and sum-frequency vibrational spectroscopy tests showed that both the basal and end planes had strong natural hydrophilicity, while the zeta potential of the basal plane was lower than that of the end plane, and the dodecylamine was more tightly arranged on the basal plane, showing a better adsorption effect than that of the end plane. Quantum chemical calculations showed that the oxygen atom activity of the basal surface was stronger than that of the end surface, which made it easier for the dodecylamine molecule to be adsorbed on the basal surface. Conclusion This article provides a fundamental theoretical basis for improved lepidolite flotation based on crystal anisotropy.