Abstract: In view of problems of poor stability, easy to be influenced by interference and bad tracking of desired trajectory existed in excitation controller of synchronous generator based on open-loop iterative learning control, an excitation controller of synchronous generator based on open-closed-loop PID iterative learning control and power system stabilization was designed. A closed-loop feedback control was introduced based on open-loop iterative learning control, current control input was obtained by the last error of input and output and current output error, so as to constitute open-closed-loop PID iterative learning control. Meanwhile, additional positive damping signal provided by power system stabilization was used to improve stability of voltage and power angel of exicitation control system of synchronous generator. The simulation result shows that the excitation controller has strong robustness and improves stability of the system.