Abstract: The day-ahead and intraday optimal dispatch problems of active distribution network are studied. Firstly, the dispatch and control framework that DMS controls overall situation meanwhile regional dispatch and control terminals regulate local regions is constructed. A two-stage dispatch strategy coordinating economy and security is adopted. Day-ahead economic scheduling is carried out to reduce active distribution network (ADN) operation cost. In intraday stage, normally each region tracks day-ahead scheduling and implements the regional dispatch correction. When voltage violation occurs, distribution management system performs the global adjustment to eliminate the violation. Mathematical optimization models with day-ahead economic dispatch, intraday regional power correction and global voltage adjustment are established. Harmony search algorithm is applied to solve the dispatch model. Finally, a case is studied to verify that the proposed approach can be applied to solve two-stage dispatch and ensure the economic and secure operation of ADN.