The invention discloses a preparation method of green pesticide fertilizer. The fertilizer is mainly prepared from inorganic fertilizer, organic fertilizer, lime, magnesium chloride and/or magnesium oxide, ammonium sulfate, water soluble silicate, zinc sulfate, borax and/or boric acid, ammonium molybdate, insecticidal plant extract, filler and plant regulator through even mixing. The insecticidal plant extract is prepared from plant raw materials including ricinus communis, tripterygium glycosides, derris roots, sophora flavescens, melia toosendan, ageratum conyzoides, paprika powder and orange peel by conducting concentrating, drying, smashing, screening and even mixing on an extracting solution prepared through a water extracting process. The pesticide fertilizer prepared through the method is comprehensive in nutrient and reasonable in ratio, the damage of crop underground harmful insects can be effectively prevented and treated, crop yield is increased, the farmland ecological balance can be effectively protected, and soil hardening, soil loss, soil depletion and other problems are prevented.