Abstract: Pure kaolinite flotation test，Zeta potential measurements，IR spectra and the MS 6.0 molecular dynamics simulation are conducted to study the flotation behavior and interaction mechanism of dodecyl-amine ethoxylate (AC1201) and dodecy-lamine hydrochloride (DAH) on coal kaolinite.The results show that AC1201 can separate kaolinite effectively at lower concentration of 750 compared with DAH.Based on the MS simulation，the adsorption models of DAH and AC1201 on kaolinite (001) plane were constructed and optimized.It shows that the contact area of AC1201 on kaolinite (001) plane is larger than DAH，the minimum distance between AC1201 and the kaolinite (001) plane is less than DAH.In addition，higher adsorption energy will be released when AC1201 is adsorbed on kaolinite surface.The theoretical computations match remarkably well with the experimental results.Therefore，it can provide a theoretical basis for exploring new reagent in kaolinite flotation.