The invention provides a process for purifying an antigen of a foot and mouth disease vaccine, comprising the following steps: (1) under the asepsis control, adding chloroform into foot and mouth disease virus liquid used for preparing a purified virus antigen, wherein the volume of the chloroform is 0.5 percent to 2 percent of the volume of the foot and mouth disease virus liquid, stirring and mixing; (2) standing the mixture for 3 to 24 hours at 2 DEG C to 8 DEG C and then separating the mixture to obtain supernatant; and (3) centrifugally treating the supernatant to obtain the purified virus antigen. The foot and mouth disease vaccine with improved immune effect and safety can be obtained by obtaining the purified virus antigen, inactivating the antigen and preparing the vaccine according to the process for purifying the antigen of the foot and mouth disease vaccine.