The invention discloses inorganic pesticide, and relates to the technical field of chemical engineering. The inorganic pesticide comprises the following ingredients in parts by weight: 25 to 40 parts of ammonium chloride, 15 to 25 parts of sodium chloride, 5 to 10 parts of potassium sulphate, 3 to 7 parts of copper sulphate, 5 to 13 parts of cupric oxide, 1 to 5 parts of zinc oxide and 800 to 1000 parts of water, wherein the weight ratio of the sodium chloride to the potassium sulphate in the inorganic pesticide is 3:1. The inorganic pesticide is prepared from the ammonium chloride, the sodium chloride, the potassium sulphate, the copper sulphate, the cupric oxide and the like. Through optimizing the mixture ratio of each ingredient, the prepared inorganic pesticide has the advantages that the cost is low; the safety is high; the effect is permanent; no residue is left.