A simulation model of the condenser in a 600MW supercritical thermal power plant was developed by using Matlab/Simulink. The important parameters such as condenser pressure, hot well water temperature and cooling water temperature were calculated by using this model. The simulation results under different operating conditions were compared with design parameters, and the relative errors were within -0.2% and +0.2%. This shows that the simulation model developed in this paper is reasonable. The dynamic performance and off-design performance of the condenser were studied by using the simulation model, which would be useful for the optimal operation of the condenser. The model of the condenser, which was developed based on the modular modeling method, would be an important basis for the simulation of the whole power plant.