The present invention discloses a synchronous generator excitation control method based on a fuzzy sliding mode. The method comprises: the step 1, establishing each unit simplification model and a fuzzy sliding mode controller model of a synchronous generator excitation system; the step 2: taking the error e1 of the feedback voltage U and the given voltage U0 at the end of a synchronous generator as the input of a sliding mode variable structure control portion, and taking the e1 and the (img file='DDA0001336670490000011. TIF' wi='36' he='63'/) as the input of a fuzzy control portion; the step 3: obtaining an excitation voltage Uf after overlapping of the fuzzy control output us and a sliding mode variable structure; the step 4: obtaining the excitation voltage UF of the synchronous generator through processing the feedback voltage U by employing a power amplification unit; and the step 5, taking the UF as the input of the synchronous generator unit, and obtaining the actual output voltage UG of the synchronous generator, wherein the actual output voltage UG of the synchronous generator is taken as the input of the voltage measurement unit to obtain the feedback voltage U at the end of the synchronous generator. The synchronous generator excitation control method based on the fuzzy sliding mode ensures the excellent static and dynamic response capability of the generator system.