According to the intraday short-term load forecast， ultrashort-term load forecast， maintenance information and the grids topology information while referring to the day-ahead generation plan curve and making use of the long period and short period optimization results， the intraday dispatch system fulfils the intraday generation plan and real-time dispatch. The current operating plan（COP） concept is introduced to store the day-ahead plan， long period plan and short period plan in the current generation plan in the form of cover. It is ensured by the COP that the ultimate operating plan has inherited the advantages established by the short period optimization boundary condition while making up for its poor global optimization effects by correlating the optimization results of the three. The system has realized automatic closed-loop control of having the information released by the power plant automatically sent to the optimizing engine after getting checked and approved by the dispatcher and directly dispatched to the power plant for execution. Hence reduced dispatcher workload and increased accident handling efficiency.