The invention discloses a composite synergy sterilization composition containing boscalid and trifloxystrobin, and applications thereof. The sterilization composition adopts boscalid and trifloxystrobin as main effective components, wherein a weight ratio of the boscalid to the trifloxystrobin is 1-90:1-90. The sterilization composition has the following characteristics that: the sterilization composition can be used for prevention and control of cereal plant diseases, fruit tree plant diseases and vegetable plant diseases, and has a high synergy effect, wherein drug resistance of bacterial is overcome and delayed, sterilization is rapid, an effect lasting period is long, an application cost is reduced, and a prevention and control effect is significantly better than a prevention and control effect of use of a single agent; and the sterilization composition can be used for prevention and control of fungal plant diseases in crops, particularly for powdery mildew, botrytis cinerea, sclerotium disease, rot disease, rust disease, glume blight, web blotch, downy mildew, rice blast, drooping disease and other fungal plant diseases, wherein the obtained effect is better than the effect of use of a single agent.