The large inertial impulse generator has the problem of excitation control. To solve this problem, a self-adaptive PID control method of whale optimization is proposed. According to the working characteristics of pulse generator and the basic requirements of excitation control, a simplified single-input single-output linear excitation control system of pulse generator is established based on the second-order name-value model of reaction generator parameters varying with speed. The PID control method based on classical control theory is adopted for the system. In order to improve the response time and control accuracy of the system, a parameter self-adaptive PID is designed which adjusts parameters automatically with the error. For the tuning of parameter adjustment coefficient, an optimization problem is constructed with the time weight error integral as the optimization objective and the parameter adjustment coefficient as the optimization variable, and the whale optimization algorithm (WOA) is used to solve the problem. Finally, the control method is simulated, and compared with the whale optimization PID, the rise time of the excitation response under no-load increases from 1.21 s to 0.88 s, and the steady-state error is similar. Under load, the rise time increases from 2.01 s to 1.60 s, and the steady-state error decreases from 4.04% to 1.96%. The effectiveness of the proposed method is verified.