Wind load is the control load for the design of super-large cooling towers. The value of the wind load inside the tower only considers the normal wind conditions. In order to study the suction distribution and flow field mechanism in a super-large cooling tower under a typhoon， a multiple nested mesoscale weather research and forecast（WRF） model is used to simulate the high spatiotemporal resolution of the typhoon “Megi”， and the wind velocity profile of the simulated area is obtained based on the least squares fitting. The 220 meter cooling tower，the highest in the world， at Shanxi Lu’an Power Plant is taken as the research object. Three-dimensional （3D）CFD wind field simulations of this tower under normal wind and typhoon are performed based on the mesoscale microscale nesting technology. Based on this， the differences and causes of flow field characteristics， energy distribution， drag coefficients and wind resistances in towers under normal wind and typhoon are compared. The 3D distribution characteristics of the wind pressure coefficient on the inner surface are compared and analyzed. Finally， suggestions for suction values in large-cooling towers under typhoons are given. The results show that the WRF-CFD coupling mode can effectively simulate the near-ground 3D wind field of super-large cooling towers under typhoons. The recommended values of the overall internal pressure coefficients at 0%， 15%， 30%， and 100% louver air permeability are -0.61， -0.36， -0.34， and -0.42，respectively.