In order to predict the heat generation of each heat source and the temperature distribution of components of a dual clutch transmission, a coupled model to simulate the bearing forces, power loss and heat transfer of the transmission was developed based on the theory of thermal network, and validated by comparing the simulation results of the total power loss and the temperature of some chosen tested points under steady and transient operation conditions with the experimental results. The results show that the numerical total power loss is in good agreement with the test results under steady operation condition, and the variation trend of the numerical results under transient condition is same as the test results; the numerical temperature of each tested point under steady and transient working conditions is in good agreement with the test results.