The present invention provides a bactericidal composition with synergistic effect. The composition contains two active ingredients A and B. The active ingredient A is benziothiazolinone. The active ingredient B is one of benthiavalicarb isopropyl, zoxamide, prothioconazole, boscalid, imidazole cycloheximide, fluopicolide, famoxadone, pyraclostrobin, picoxystrobin or fluazinam. The weight ratio of the two ingredients is (1:50) to (50:1). As shown in an experimental result, the bactericidal composition provided in the present invention has obvious synergistic effect, needs a small dosage, and needs lower cost, and is capable of effectively preventing and treating certain special fungal diseases of crops such as grains, vegetables and fruits, thereby expanding the sterilization spectrum, delaying the fungal resistance and improving the prevention and treatment effect.
