Abstract: This is an essay in the field of mineral processing engineering. The flotation method is applied to reduce ash content and purify pyrolysis carbon black from waste tires in this study. The effect of different operating factors on carbon black flotation was explored, and the phase and morphology of different flotation products were measured by various characterization methods. Results show that 62.32% yield of clean carbon black and 17.29% ash content for flotation concentrate were obtained, and 37.68% yield of flotation tailing and 23.32% ash content were obtained as well under the optimal flotation conditions were of 20 g/L of concentration, 500 g/t of collector, 1500 g/t of foaming agent, 9 min of froth skimming time and 0.25 m³/h of aeration amount, and the removal rate of quartz is 75.49% and the removal rate of calcium carbonate is 66.23%. Minerals including quartz and calcite were effectively removed by flotation, The amount of aeration had more significant impact on the test. This study indicates that flotation can be well used for reducing ash content of pyrolysis carbon black from waste tires which is proved to be an effective ash reduction pretreatment method.