A hybrid control approach aimed at realizing multi-objective approximation of optimization for the control and dispatch of power systems is presented. The essence of the approach is to have the unsatisfactory states defined as events and the problems of optimization approximation are converted to problems of handling and elimination of events. By adopting the layered control mode， the concept of the control command（issued from the supreme decision-making and commanding layer） and operating instructions（issued from the intermediate operation layer） is proposed and a complete event handling framework is developed so as to attain the goal of eliminating events. The framework of composition of the advanced EMS（AEMS） is also described， with the functions and operation mechanisms of all the component parts in the framework specified. In view of the design， implementation and operation of the AEMS， the basic features they must possess are pointed out while the relationship of tolerance between AEMS and EMS is dealt with. The AEMS of Shanghai Power Grid based mainly on the hybrid control theory and method proposed is explained as a typical case.