The invention discloses a strong-flavor distiller grain bio-organic fertilizer, which is mainly prepared from the following raw materials by weight: 40-60 parts of strong-flavor liquor distiller grain, 20-40 parts of auxiliary materials, 1-2 parts of dust urea, 0.1-5 parts of waste ammonia water, 0.5-1 part of a special decomposition agent, 5-10 parts of grease production wastes and 2-5 parts of calcium superphosphate. The preparation method of the organic fertilizer comprises the following steps: raw material mixing, high-temperature decomposition, cooling, aging, initial product adjustment and finished product delivery. According to the organic fertilizer, chemical waste is used for pH value adjustment and carbon-nitrogen ratio pretreatment of fermentation. Firstly, through the combination of enzyme and bacteria, the decomposition time is shortened, the water-soluble humic acid in the product is improved, and the fertilizer efficiency is improved; secondly, the technology can fully utilize chemical waste, and the production cost is lower. The organic fertilizer is used for fruits, vegetables, tea and other crops, can effectively improve the rhizosphere soil environment of the crops, promotes the absorption of various mineral elements by root systems, promotes the growth and development of the crops, and improves the yield and quality of the crops.