The invention provides an inactivator for foot and mouth disease viruses. The inactivator is BEI and FA. The invention further provides an inactivation method for the inactivator. The inactivation method comprises the steps of performing primary inactivation on foot and mouth disease virus liquid to be inactivated by the inactivator according to claim 1 or 2 for 5.5-6 hours, putting the virus liquid subjected to primary inactivation into another container, performing secondary inactivation on the virus liquid by the inactivator according to claim 1 or 2 for 5.5-6 hours, and adding sodium thiosulfate for blocking after inactivation. According to the inactivator disclosed by the invention, the vaccine production period can be shortened, the vaccine production cost can be reduced, and the purpose of enhancing the vaccine effect is fulfilled; the requirement on industrial large-scale production for foot and mouth disease vaccines within shorter time is met.