The invention belongs to the technical field of organic fertilizer production and in particular relates to a method for harmless production of an organic fertilizer from pigs dying from diseases. Themethod comprises the following process procedure steps: (1) performing dismemberment and sterilization on a raw material; (2) preparing a fermentation decomposition liquid; (3) performing composting decomposition; (4) extracting a decomposition liquid. According to the method, bodies of pigs dying from diseases are cut off, only fat and meat pieces are maintained, organs and blood are abandoned, the pigs dying from diseases are decomposed into a liquid fertilizer and solid residues under the oxidation decomposition functions of multiple microorganism colonies, and finally an organic fertilizeris prepared through filtration and sterilization. The method is simple in production process, relatively low in treatment cost, relatively high in economic value, very safe in process procedure and free of human body infection risk, and the content of harmful bacteria generated after sterilization of the produced organic fertilizer is also reduced.