Abstract: In order to solve the problem of uneven distribution of flow field in the throat of the condenser and affecting the working performance of the condenser, a 1000 MW coal-fired generator set was taken as the prototype, and the CFD simulation software was used to simulate and analyze the exhaust channel of the entire steam turbine, and an optimization scheme was obtained to improve the uniformity of the flow field at the outlet of the throat of the condenser by arranging the diversion device in the throat of the condenser. The velocity uniformity coefficient of the condenser throat outlet increases from 0.5949 to 0.6765 after the unit uses the optimized scheme. The end difference of the condenser decreased from 4.92 ℃ to 3.38 ℃, and the total heat transfer coefficient of the condenser decreased from 2357.69 W/(m²·K) increased to 2966.27 W/(m²·K), the condenser pressure was reduced by 0.31 kPa.