A stagewise algorithm is proposed for the solution of multicomponent multistage batch distillation problems. In order to make the algorithm more precise and flexible, a generalized implicit Euler equation is implemented for numerical integration of the process variables on each stage at succeeding time steps. An overall normalized theta method is also employed to accelerate convergence for each time step. The relative performance of the proposed method compared with the Runge-Kutta method is shown using a numerical example; the CPU time can be decreased by up to 1/300. Comparison of the simulation results with the experiment suggests the adequacy of the proposed method.