Selenium-rich cadmium-reducing lead-reducing mineral bio-organic fertilizer and preparation method thereof

The invention provides a selenium-rich cadmium-reducing lead-reducing mineral bio-organic fertilizer and a preparation method thereof, and relates to the technical field of selenium-rich fertilizer. The selenium-rich cadmium-reducing lead-reducing mineral bio-organic fertilizer comprises the raw materials: electrolytic manganese residues, electric coal ash, limestone, phosphate ore, sugarcane filter mud, distillers' grains, tobacco ribs and earthworm manure. The preparation method comprises the steps of harmless treatment of the electrolytic manganese residues, preparation of pure natural phosphate ore, mixing, fermentation, after-ripening, preparation and other processes. The electrolytic manganese residues are taken as a main raw material, other raw materials are taken as auxiliary materials, and the selenium-rich cadmium-reducing lead-reducing mineral bio-organic fertilizer containing 18 or more nutrient elements and organic matters such as organic nitrogen, phosphorus, potassium, calcium, magnesium, sulfu