The invention relates to a pest-control compound pesticide and a preparation method thereof, the pest-control compound pesticide is prepared from rhizoma arisaematis, mustard, semen strychni, Lysimachia fortunei and other as raw materials through crushing, mixing and other steps; through ratio optimum, the raw materials are interacted to play a significant pest killing role, the pest-control compound pesticide has the advantages of simple preparation method, low cost, very extensive material sources, natural degradation and good environmental compatibility, avoids pesticide residues of agricultural products, may not damage ecological balance after long-term use, and is easy to use.