The invention discloses a hull prepared insect-prevention type special sweet potato compound fertilizer. The fertilizer is prepared from 200-300 parts of hulls, 76-115 parts of urea, 162-244 parts of monoammonium phosphate and 336-504 parts of potassium sulfate. The invention further discloses a preparation method of the hull prepared insect-prevention type special sweet potato compound fertilizer. The hull prepared insect-prevention type special sweet potato compound fertilizer has the advantages that hulls serve as main raw materials to be directly used, a chemical fertilizer formula is added, granulated fertilizer is made through smashing, burdening, mixing, pelleting, drying, screening, cooling and other technologies, controlled-release phoxim is used for spraying, and finally finished products are packaged. When the technology is applied for production, the advantages that alkaloid components in hull waste can be reserved to the maximum extent, and the inspect killing effect and the sterilizing effect of the product can be enhanced easily; the hull waste is subjected to resource utilization so that chemical insecticide can be replaced or partially replaced, prevention and treatment on underground insects in the sweet potato planting process is guaranteed, the yield is increased, and the quality is improved.