Abstract: The triboelectrostatic beneficiation tests of fly ash were designed by Design-Expert friction based on decar- burization efficiency index. Quadratic model between the decarburization efficiency and test factors was established by the test of the Box-Behnken design scheme. The test factors were in-flow velocity,friction wheel speed,correct flow wind speed,plate voltage,collection chamber wind speed and collection chamber width. The response surfaces of sec- ond order interaction between different variables on the decarburization efficiency were obtained and the interaction re- lationships between variables were analyzed. Decarburization efficiency was used as the optimization index to get its maximum value. The optimal decarbonization effect,decarburization efficiency of 128. 51% ,is obtained when the in- flow velocity is 3. 7 m / s,friction wheel speed is 5 150 r / min,correct flow wind speed is 1. 8 m / s,plate voltage is 40 kV,collection chamber wind speed is 1. 0,1. 5,1. 5 m / s and collecting chamber width is 2,1,3 cm. The predicted value based on the model is close to the test value.