The invention relates to a catalyst, in particular to a compound catalyst, a preparation method and application thereof, and belongs to the field of chemical technology. The invention discloses a synthetic method of a novel compound catalyst consisting of a CuV2O6 nanobelt material synthesized by using a hydrothermal method and an acid mesoporous poly-ionic liquid. The compound catalyst prepared from the CuV2O6 nanobelt material and the acid mesoporous poly-ionic liquid through mechanical mixing is applied to a reaction for generating 2,5-furan dicarboxaldehyde through fructose one-step conversion. The used catalyst is cheap and easy to get; the reaction is short in time, efficient and energy-saving; the yield of target product is high, and relatively few byproducts are generated; air or oxygen serves as an oxygen source, and the economic and environmental costs are low; the product and the catalyst are easy to separate, and the aftertreatment is simple; the catalyst is easily reused, the waste remission is little, and the catalyst is green and environmentally-friendly; the catalyst is extremely low in requirement for equipment and little in equipment investment, is beneficial to industrial development, and has extremely important application prospect.