The invention relates to a power grid dispatching operation lean evaluation system and belongs to the power system technical field. With the continuous expansion of power grids, the operation characteristics of the power grids are increasingly complex, and the difficulty of the dispatching operation lean management of the power grids is also increased sharply. The system includes an evaluation index system building module, a classifying and normalizing module, an intensional weight calculation module, a structural weight calculation module, a comprehensive weight calculation module and an evaluation calculation module; the classifying and normalizing module classifies indexes and normalizes the indexes; the intensional weight calculation module determines the intensional weight of an evaluation index system; the structural weight calculation module determines the structural weight of the evaluation index system; the comprehensive weight calculation module obtains comprehensive weight; and the evaluation calculation module obtains an evaluation result. With the power grid dispatching operation lean evaluation system provided by the technical schemes of the invention adopted, the lean level of power grid dispatching operation can be comprehensively and reasonably reflected, and guidance can be provided for the optimal operation of the power grids.