The invention discloses a frequency modulation feedback Nash equilibrium control method based on a coevolution algorithm. The control method includes the steps that step1, in consideration of a speed controller dead zone, control action amplitude limit, unit creep speed constraint and other engineering practice factors, a differential game model between a primary frequency modulation and a secondary frequency modulation in an IEEE two-area interconnection system is built; step2, the coevolution algorithm is adopted for solving the differential game model, with kinds of complex constraint, between the primary frequency modulation and the secondary frequency modulation in the IEEE two-area interconnection system, and a feedback Nash equilibrium solution of the differential game model is obtained; step3, the obtained feedback Nash equilibrium strategy serves as a primary frequency modulation control quantity and a secondary frequency modulation control quantity of an area, the conflict anti-tune problem between the primary frequency modulation and the secondary frequency modulation is effectively solved, and therefore coordination control between the primary frequency modulation and the secondary frequency modulation of an electric system is achieved. The frequency modulation feedback Nash equilibrium control method has the advantages of reducing unit wastage and achieving a good control effect.