The invention discloses a comprehensive evaluation method for coupling and decoupling a ring of an electromagnetic ring network based on an entropy weight method and a grey relational degree in the field of power system operation and control. The comprehensive evaluation method comprises the steps of determining an operation evaluation index of an electromagnetic ring network; according to the determined index acquisition data, pre-processing original data; obtaining the objective weight of the index using an entropy weight method; obtaining a grey relational coefficient matrix of a system by using a gray relative analysis method; and solving for the entropy grey relational degree and finally determining an operation scheme of the electromagnetic ring network. The method is simple, practical and fast, and has an important significance in terms of evaluation of the scheme of coupling and decoupling the ring of the electromagnetic ring network in the power system.