A method of producing black phosphorus which includes the steps of: weighing and mixing reaction raw materials which comprises metallic tin, red phosphorus and monocrystalline iodine, wherein a weight ratio of tin: red phosphorus: iodine is 0.6-3.5: 5-45: 0.1-0.8; feeding the mixture to a high-temperature resistant metal reaction tube; removing air by introducing inert gas and sealing the reaction tube tightly; placing the metal reaction tube inside a muffle furnace for carrying out calcination reaction by first increasing a temperature at a preset rate to a maximum temperature and keeping warm and then decreasing a temperature at a preset rate and keeping warm, then to room temperature so that the black phosphorus is produced. The conversion rate is very high and the quality of the produced product is classified as high quality.