Abstract: In view of the problem that initial control signal is defined by experience in traditional excitation controller of synchronous generator based on iterative learning control algorithm, the paper proposed a design scheme of excitation controller of synchronous generator based on lazy learning type iterative learning control algorithm. The scheme introduces lazy learning algorithm into iterative learning control algorithm and uses lazy learning algorithm to calculate initial control signal, so as to reduce error between initial control signal and the ideal one. The simulation result showed that the controller has quick convergence speed and higher ability of maintaining terminal voltage.