The invention discloses a compound fungicide composition containing tridemorpholine as a main component and its application. The compound fungicide composition is composed of component A and component B, wherein component A is tridemorpholine, and component B is any of difenoconazole, propiconazole, tebuconazole and myclobutanil. One, wherein component B also includes auxiliary materials, and the mass ratio of component A:component B is 1-40 parts:99-60 parts to form a compound composition. For the application of the composition, the above-mentioned component A and component B are weighed and mixed according to the mass ratio, and filled into 100 parts with water or fillers, which can be made into different application dosage forms, and the dosage forms include: water emulsion, microemulsion, Water-dispersible granules, wettable powders, suspending agents, emulsifiable concentrates, simple formula, low cost, easy to use, less drug residues on crops, production in line with environmental protection requirements, suitable for prevention and treatment of vegetables, wheat powdery mildew and banana leaf spot, mixed The control effect of the preparation is 2-3 times higher than that of the two single doses.