In order to coordinate the optimization of power transmission and distribution equipment in the operation of production scheduling maintenance plan,this paper designs a maintenance plan optimization decision system.Based on multi-source information which includes smart grid dispatching technical support system (D5000),generation and transmission equipment maintenance plan,base date of maintenance plan can be automatically generated.Then optimization and adjustment for maintenance plan are realized through multiple class scheduling plan security checking calculation method.Also,power supply capacity assessment of the grid is achieved.On basis of security and stability,the power network loss can be decreased by optimization of maintenance plan.So,the grid operation economy can be improved.Since the system was put into operation and dispatched production of the power grid,it has realized the optimization preparation of annual/monthly power transmission and transformation maintenance plan.Also it has improved the safety and economic operation level and production efficiency.