The invention discloses an acidification desalting process for separating or extracting pyruvic acid from a fermented liquid of pyruvic acid by an electric infiltration method and an electric infiltration device thereof. The process comprises the steps of pretreating the fermented liquid and desalting the fermented liquid by using an electric infiltration method. The device comprises an electric field, a membrane stack arranged in the electric field, and four different types of chambers arranged in the membrane stack, wherein the electric field is formed by a positive electrode and a negative electrode, and the membrane stack is formed by an anionic membrane and a cationic membrane. Compared with the prior art, the invention has the advantages that an electric infiltration method is used for separating or extracting pyruvic acid from the fermented liquid of pyruvic acid; the process is simple, and a traditional decalcifying process with sulfuric acid is abandoned; the yield of pyruvic acid is high, and the product does not contain sulfate ions and has a good quality; the resultant waste is little, and thus the process is friendly to environment; and the working environment of workers can be improved greatly, the labor intensity can be reduced, and the operation safety index is enhanced.