The invention provides an evaluation method based on a voltage reactive power control system in a grid system. Weights are distributed through the utilization of the fuzzy linear transformation theory and the maximum membership degree principle, by taking factors relevant to an evaluated object into consideration and according to the degree of influences of different indexes on the evaluated object, and then reasonable comprehensive evaluation is given. The method includes the steps that firstly, data of the voltage reactive power control system in a grid are acquired; secondly, an index system of a hierarchical model of first level indexes and second level indexes is formulated; thirdly, system running is analyzed and summarized according to running data, analysis data and running state information of all modules, and then running state parameters and the running state of the voltage reactive power control system are acquired, wherein the first level indexes and the second level indexes in the index system serve as analysis and computation objects of the voltage reactive power control system; fourthly, a judgment set of a classification model is determined; fifthly, a comprehensive analysis hierarchical structure is formed through the Delphi method; sixthly, the weights of the indexes are determined; seventhly, comprehensive evaluation of the highest layer A of the comprehensive evaluation index system is computed according to a fuzzy comprehensive evaluation method and model.