NOVELTY - Preparation of solid biological organic fertilizer by sludge as raw material involves using sewage sludge and sugar refinery filter mud as raw materials, and fermentation of sludge and refinery filter mud using biological stain to form a solid biological organic fertilizer.    USE - For preparation of solid biological organic fertilizer using sludge as raw material (claimed).    ADVANTAGE - Through the method, the sludge and mud of the sugar factory produced by municipal sewage treatment plant produces harmless, odorless, good fertilizer. The bio-organic fertilizer produced is inexpensive. The method allows protection of the environment and can produce certain economic benefit.    DETAILED DESCRIPTION - Preparation of solid biological organic fertilizer by sludge as raw material involves using sewage sludge and sugar refinery filter mud as raw materials, and fermentation of sludge and refinery filter mud using biological stain to form a solid biological organic fertilizer. The method involves: 1) taking raw material proportion content of: moisture content of 75-85%, sludge of 40-59.9%, sugar refinery filter mud of 40-59% and biological strain of 0.1%; 2) fermenting: mixing the sludge and refinery filter mud, then adding biological strain, mixing, and stirring uniformly, and aerobic fermentation of material mixture, in ferment process, through metabolism of microorganism, conversion of organic matter in the sludge to a humus-rich plant nutrient, metabolite of final reaction is carbon dioxide (CO2), water (H2O) and heat, bio-refractory decomposition of organic substance at the same time with heat produce, fermenting the material, temperature can rise to more than 55 degrees C, and maintaining for more than 3 days for not only fully killing the pathogenic microorganism, and killing pathogen, parasite eggs and weed seed, heating the material to maintain continuous high temperature, and reducing the water content of the material continuously, at last to get a water content of less than 30%, to give biological organic fertilizer product.