The present invention provides a sterilization composition with synergism. The composition contains two effective components: A and B. The active component A is polyhexamethylene biguanidine hydrochloride or a salt compound acceptable in agriculture, the active component B is selected from one of cyprodinil, epoxiconazole, benthiavalicarb-isopropyl, zoxamide, azoxystrobin, prothioconazole, difenoconazole, fenamidone, polyoxin, iprodione, activated ester, dithianon, pyraclostrobin, trifloxystrobin, picoxystrobin, fluazinam, and thifluzamide or dimethomorph, and the weight ratio of the two components to one another is 1:50-50:1. The test result shows that, the sterilization composition provided by the present invention achieves obvious synergism, and more important, the application amount is reduced, and the use cost is decreased. By compounding bactericides with different mechanisms of action and different action manners, the application amount of each single bactericide is effectively reduced, thereby facilitating extension of the bacteriocidal spectrum, prolonging of the resistance to funguses, and improvement of the prevention and curing effect.
