The invention relates to a preparation method of a special organic fertilizer for southern sand pears. The preparation method comprises the following steps: firstly, treating crushed vernicia fordii fruits by a detoxification process, then adding a compound mixed bacteria solution, and fermenting for 5 to 7 days to obtain a decomposed fermentation substance; secondly, mixing the decomposed fermentation substance with natural sheep manure, further adding the compound mixed bacteria solution, and fermenting for 10 to 15 days to obtain a fermented organic material; thirdly, further mixing the fermented organic material, sand pear tree rhizosphere probiotic, humic acid and urea, adding the compound mixed bacteria solution, and fermenting for 5 to 7 days to obtain a target organic fertilizer. The preparation method disclosed by the invention has the advantages of easiness in material obtaining, simple production equipment, short preparation time and lower cost. By using the special organic fertilizer for the sand pear tree, prepared by the preparation method disclosed by the invention, physicochemical properties of soil in a pear garden can be effectively improved, and activation and utilization of the fertilizer are promoted, thereby promoting healthy growth of the pear tree, improving the yield and the quality of pears, enabling the yield of the pears to be increased by 24.99 to 49.38 percent, and enabling soluble solids to be increased by 22.77 to 26.53 percent. The special organic fertilizer is a first choice for efficient management of pear gardens in a hilly red soil region of southern China, and has a broad application prospect.