The invention discloses a proportional-integral-differential (PID) prediction function-based excitation control method, which is used for an excitation control system for a synchronous generator. By combining characteristics of PID and prediction function control, a PID form-based prediction function controlled target function is provided, and the optimized controlled quantity is obtained by optimized calculation, and is taken as a control end input signal of a silicon controlled (or a full-control device) in the excitation control system so as to control the excitation current of the synchronous generator and further influence the terminal voltage thereof. An excitation controller acquired by the method has structural characteristics of proportion, integral and differential in a broad sense, has respective advantages of the PID and the prediction function control, and is convenient to implement. The method overcomes the defects that the conventional prediction control method has highon-line calculated amount and the PID control method has a limited regulating range, and is a novel and effective control strategy for stabilizing a power system.