The invention relates to a compound disinfectant for veterinary use. The compound disinfectant is prepared from the following components: aldehydes, zinc ricinoleate, quaternary ammonium salt, phenoxyethanol, a chelating agent, nano-photocatalyst, aspartase, farnesol, a surfactant, and purified water which is added to a full-dose volume; a preparation method of the compound disinfectant comprises the following steps: (1) firstly, adding the purified water into a mixing container, adding the aldehydes, and enabling the aldehydes to be completely dissolved; (2) adding the chelating agent and the surfactant into step (1), and uniformly stirring; (3) then adding the zinc ricinoleate, the nano-photocatalyst, the aspartase and the farnesol into step (2), and uniformly stirring; (4) adding the quaternary ammonium salt and the phenoxyethanol into step (3), and uniformly stirring; filtering, and filling to obtain the disinfectant. The disinfectant provided by the invention has the advantages of high efficiency, small corrosiveness and the like, and can be used for disinfecting livestock and poultry environments, disinfecting equipment and the like.