In order to accurately calculate the braking efficiency factor of drum brake shoe of heavy truck, virtual prototyping of a heavy truck's brake is demonstrated. The requirements for brakes include not only its performance but also its comfort, serviceability and working lifetime, which must be high. The finite element analysis software ANSYS and the multi-body system simulation software MSC.ADAMS were used to establish the drum brake nonlinear 3D simulation model. The model was built by developing joint program module between the rigid shoe and the flexible lining and nonlinear contact force program module between the lining and the rigid drum. Using this model, the simulation was executed for the drum brake of 32t heavy duty truck. The results show that the simulated braking efficiency factor coincides with experimental results of the braking efficiency factor of the heavy truck drum brake.