To realize the multiple time-scale coordination dispatching mode, the extended short-term optimal dispatching strategy based on the model predictive control method (MPC) is studied. The object functions of the model are the minimizations of the units’ cost and emission expense. The initial strategy of the real-time dispatching is decided by solution of the multi-period optimal problem in the periods ahead, and then the real dispatching condition and the new forecasting information being taken as the feedback information are used to execute circling optimal dispatch. The day-ahead dispatch time-scale and the real-time time scale are cooperated to deal with the effect of forecasting information fluctuation on system dispatch. The case study results show that considering the multiple period optimizations as a whole could allocate load among the units reasonably and improve the economy of the power plant operation. At the same time, the robustness and convergence of MPC method is testified.