Abstract: As a pretreatment link in flotation process, pulp preconditioning exerts a significant bearing on flotation effect. For exploring the effect of intensification of flyash pulp conditioning obtained with the use of the impact-flow mixer, the flyash from Jinzhushan Power Plant of Lengshuijiang City, Hunan Province is selected as the object of study. Test is made with the forced mixing and conditioning device to investigate and evaluate the effect of mixing frequency on absorbing capacity of collector, contact angle of flyash, recovery rate of unburnt carbon, and loss on ignition of tailings, as well as the effectiveness of the method in intensification of pulp conditioning process, and its influence on flyash flotation behaviors. As evidenced by test result, within the range of the mixing frequencies under study, at a frequency of 50 Hz, a best pulp conditioning result can be expected, with the absorbing capacity of collector, flyash contact angle and cumulative recovery of unburnt carbon all reaching respectively a maximum level of 1.90 mg/g, 63.81°and 94.91%, and a loss of tailings on ignition reduced to a minimum of 3.68%.