The invention discloses a synthesis method for preparing a non-imidazole ionic liquid for a proton exchange membrane fuel cell electrolyte. The synthesis method comprises the following steps: dialkyl sulfate and pyridine react, a product generated after the reaction reacts with a KAC ethanol solution or an NaAC ethanol solution, the generated precipitate is removed by filtering to obtain a colorless and transparent solution, an acid with a proton conduction function is added in the solution, and the acetate of the salt is replaced to obtain the ionic liquid with cations as non-imidazole ions. The adverse effects of an imidazole ionic liquid on proton exchange membrane fuel cell catalysts are avoided, which can be verified through a cyclic voltammetry electrochemical method and other electrochemical methods. The ionic liquid is carried in a PVDF membrane to perform a single battery experiment, and the result shows that the ionic liquid is taken as the ionic liquid for the electrolyte, so that the performance is obviously improved, and compared with the imidazole ionic liquid, the highest power density can be improved by about 15 times.