The invention discloses a germicide composition. The germicide composition consists of an active ingredient (A), namely fluazinam, and an active ingredient (B), namely any one of myclobutanil, difenoconazole, tebuconazole, propiconazol, hexaconazole, flutriafol, metconazole, epoxiconazole, flusilazole, fluquinconazole, tetraconazole, triadimenol, triadimefon, diniconazole, penconazole and cyproconazole, wherein the mass ratio of A to B is 1:100-100:1. The composition has obvious synergistic effect and high prevention effect, and is applied to the prevention and control of various diseases of fruits and vegetables, particularly the prevention and control of powdery mildew.