The invention discloses a soil improvement medical fertilizer and a preparation method thereof, and an application of the soil improvement medical fertilizer in preparation of pesticides and chemicalfertilizers, and relates to the field of medical fertilizers, wherein the soil improvement medical fertilizer comprises the following components in parts by mass: 50-60 parts of fermented gelsemium elegans, 50-60 parts of fermented chinaberry seeds, 14-17 parts of fermented rice hull powder, 2.5-5 parts of soybean cake powder, 7-9 parts of oil cake powder, 15-17 parts of cottonseed cake powder, 23-27 parts of calcium superphosphate, 180-210 parts of zinc nitrate and 0.7-1.8 parts of copper sand acid. Gelsemium elegans and chinaberry seeds with traditional Chinese medicine components are utilized, the gelsemium elegans is a toxic substance and can kill bacteria and insects, a small amount of the gelsemium elegans is transferred to crops, and enters human bodies through a food chain; the gelsemium elegans is pungent and warm, has large toxicity, has the effects of removing toxicity, eliminating evil, dissipating blood stasis, relieving pain and inhibiting, so that the gelsemium elegans is suitable for liver cancer, intestinal cancer, skin cancer, osteosarcoma and the like, is beneficial to human bodies and can effectively kill bacteria and insects, and the rest components provide necessary trace elements for crops to meet the growth of the crops.