Based on analyzing of two basic modeling methods of Extended-Range Electric Bus (E_REB), this paper had established a E_REB's Forward-Simulation model, and described main sub models in detail. Basised to the parameters of a certain E_REB, the Forward model was simulated under UDDS driving cycle, and some significant characteristic curves and dynamics, economics simulation data were obtained. Compared with experimental values of the E_REB, the error was within allowable range. So the results have proven that the Forward-Simulation model was rational and practical.