The invention discloses a hydrophobia attenuated vaccine-praziquantel complex agent and a preparation method and application thereof. The hydrophobia attenuated vaccine-praziquantel complex agent comprises praziquantel, double solvents, additives and hydrophobia attenuated vaccine. According to the hydrophobia attenuated vaccine-praziquantel complex agent, on the basis that the efficacy of all effective constituents is guaranteed, the purpose of stable mixing of the water-soluble hydrophobia attenuated vaccine and the fat-soluble antiparasitic praziquantel is achieved. The preparation method is simple and feasible.