The invention relates to a desinsection composite with synergy and application thereof. The effective components are Nitenpyram and pyrethroid pesticides; the weight portion ratio of the Nitenpyram to the pyrethroid pesticides is 10:1-1:50. The desinsection composite can be processed into any preparation formulation acceptable to pesticide application; the preferable preparation formulation is wettable powder, aqueous emulsion, missible oil, microemulsion, water dispersible granule or troche, and suspending agent. The composite has remarkable synergy on pests and is used for controlling pestson plants, especially for controlling plant louse, thrips and fleahopper.