The decoupling control of the traditional Doubly-Fed Induction Generator (DFIG) based on wind turbine makes it impossible to respond to the frequency variation of the power system, the pressure of frequency modulation in power system is increasing because of the daily increasing penetration of wind power, as a result, it is of great significance to study the AGC optimal control of two-area interconnected power systems which includes DFIG. Wind power is regarded as a negative load which is incorporated into the two-area interconnected automatic generation control model, DFIG has better capability of frequency response due to the improved virtual inertia control. Moreover, the proposed PSO-GSA algorithm is used to optimize the parameters of PID controller of AGC and PI controller of the speed control block. Simulation results show that frequency regulation of DFIG could effectively relieve frequency deviation and pressure of synchronous machine in the power system. Moreover, PSO-GSA algorithm in this paper has faster convergence speed and better fitness value than PSO and GSA. The controller optimized by PSO-GSA algorithm is able to improve system frequency deviation, tie line power, area control error, overshoot and stabilization time, which enhances the stability of the power system. This work is supported by National Natural Science Foundation of China (No. 51477143).