Abstract: The holes are opened at the center point 50 cm away from the top of the conical cylinder on the inclined plane of the cyclone separator.The opening in the inlet direction of the cyclone separator is named as 0° hole which is rotated 90° clockwise from the inlet direction of the cyclone separator,and named as 90° hole,180° hole and 270° hole,respectively.The separator efficiency is adjusted by introducing interference wind into the opening of conical cylinder of cyclone separator,but the influence of the interference wind on the pressure drop of the cyclone separator is unkuown.In order to study the effect of the interference wind on the whole performance of the cycle including pressure drop,separation efficiency and bed temperature change,and get the best opening scheme,the pressure drop characteristics of a 300 MWe CFB cyclone with adjustable separation efficiency were studied by numerical simulation in this paper.Firstly,the pressure drop at different inlet velocities was simulated without interference wind,and the results were compared with the calculation results of empirical pressure drop model.The results show that the pressure drop increases with the increase of inlet velocity,and the simulation results are in good agreement with Chen-Shi model.Then the pressure drop is simulated when the inlet velocity is 7.48 m/s and the interference wind speed is 10,20 and 30 m/s at 0°,90°,180° and 270° holes,respectively.The results show that the pressure drop decreases with the increase of the interference wind speed in the 0° and 90° holes,and the pressure drop first increases and then decreases with the increase of the interference wind speed in the 180° and 270° holes.Combined with the variation of bed temperature when the interference wind is introduced into different holes,it can be considered that the 90° hole is a better reconstruction scheme.