The invention discloses an organic-inorganic environmentally-friendly 
pollution-free compound 
fertilizer and a preparation method thereof. The compound 
fertilizer comprises the following components, in percentages by 
mass: 20-25% of harmless 
livestock and 
poultry manure, 5-10% of 
earthworm excreta, 10-15% of 
humic acid, 25-30% of 
urea, 14-24% of monoammonium 
phosphate, 8-18% of 
potassium chloride,and 5-8% of 
calcium dihydrogenphoshate. The preparation method comprises the following steps: removing 
heavy metals in the 
livestock and 
poultry manure, performing harmless treatment on heavy 
metal ions through earthworms and preparing the high-quality 
organic fertilizer raw material earthworm excreta, removing 
antibiotics of the 
livestock and 
poultry manure by adopting physical, chemical and biological methods, wherein the above steps solve the problems that the 
heavy metals and the 
antibiotics pollute the environment and endanger 
human health, and performing composting 
fermentation, whereina secondary 
granulation technology is adopted to improve a 
granulation rate of the material, clay for promoting 
granulation does not need to be added, a large amount of 
liquid vapor or water does notneed to be supplemented, so that the problem of difficulty in granulation of an organic-
inorganic fertilizer is solved. The prepared product provided by the invention has the following advantages: 1,the product has a high 
nutrient content, a low 
moisture content, good particle strength and low costs; and 2, 
organic matter sources of the product are the livestock and poultry 
manure, the earthwormexcreta and the 
humic acid, compared with other organic-inorganic fertilizers, the 
fertilizer provided by the invention has diversified and 
pollution-free 
organic matter sources, facilitates being absorbed and utilized by crops.