The invention relates to a compounded synergia sterilizing composite, belonging to the technical field of pesticide. The sterilizing composite comprises an original medicine compounded by a sterilizing agent A and a sterilizing agent B, wherein the ratio of the sterilizing agent A to the sterilizing agent B is (1-90):(90-1), the sterilizing agent A is ethirimol or bupirimate, and the sterilizing agent B is any one of the following sterilizing agents: copper agent, methoxy-acrylics, triazoles, amides, pyrilamine, benzimidazole, thiocarbamate, dicarboximide, imidazole, morpholine, oxazole, ureas, pyridines, miazines, pyrroles, phthalimide, carbamates, antibiotics and others. The sterilizing composite comprises the original medicine compounded by the ethirimol or bupirimate and the sterilizing agent B, thus not only enlarging the bacteriocidal spectrum, but also slowing down the drug resistance of germs, and having obvious continuous synergia effect.