Abstract: Based on the numerical models respectively established for the steam and water side of a condenser, an innovative method was proposed to import the velocity distribution of cooling water obtained from the calculation of porous media model on water side into the porous media model on steam side to realize the coupling calculation of flow and heat transfer on both sides. A self-defined program was developed on the Fluent platform for reading the velocity distribution on water side and importing it into the steam side. A coupling simulation was conducted for the steam and water side of a surface condenser in a 600 MW unit. Results show that the coupling calculation method proposed is feasible, and the numerical simulation of condenser performance is more reasonable based on uneven velocity distribution of cooling water on the water side.