Unequal capacitance grouped capacitors have high switching flexibility and excellent reactive power regulation ability, but there are problems with complex control strategies and frequent switching of equipment. Therefore, this article proposes a reactive power optimization configuration method that coordinates the contradiction between the two. Firstly, the probability distribution curve of reactive power demand in the substation is obtained according to the substation load, and then the optimal coverage method is used to calculate the reactive power mismatch area formed by the intersection of the distribution curve and the trapezoidal curve of capacitor compensation capacity. The smaller the area, the better the flexibility of capacitor regulation.Then considering the regulation complexity index, an optimization model of unequal capacitance grouping of capacitor is established with the minimum mismatch area and regulation complexity as the objective function. The multi-objective optimization model is transformed into a single-objective optimization model by the fuzzy weighting method. The improved genetic algorithm is used to solve the problem, and the reactive power configuration scheme of the substation is obtained, which can provide decision-making basis for reactive power planners. The final case simulation verifies that the proposed method in this paper can balance the advantages and disadvantages of unequal capacity grouping by comparing it with existing literature on equal capacity grouping and unequal capacity grouping.