The gas-solid two phase flow numerical model in cyclone separator was built using open source software OpenFOAM in this study, and the simulation results were compared with the experimental data. Based on this model, the effect of the secondary wind on the separation performance of cyclone separator was analyzed. The results show that the simulation results coincide with the experimental data, and the average error of pressure drop and the separation efficiency is 9.89% and 1.33%, respectively, which proves the numerical model to be right. In addition, the secondary wind can weaken the secondary flow effectively, thus reduce the up ash loop and short circuit flow, and increase the separation efficiency of the cyclone separator. The grade efficiency of the cyclone separator increases with the velocity of the secondary wind, but the increase rate is gradually decreased. The pressure drop of the cyclone separator increases with the velocity of the secondary wind. When the velocity of the secondary wind are 15, 25, and 30 m/s, respectively, the pressure drop of the cyclone separator has reached 2 times, 3 times and 4 times of that with no secondary wind. Therefore, the energy consumption and efficiency are taken into account when introducing the secondary wind to the cyclone separator.