Belonging to the technical field of fertilizers, the invention particularly relates to an organic fertilizer special for vegetables and a preparation method thereof. The organic fertilizer comprises the following components by weight: 10-20 parts of fruit residue, 20-30 parts of bagasse, 20-30 parts of livestock and poultry excrement, 40-50 parts of crop straw, 10-15 parts of soybean meal, 10-15 parts of rapeseed oil cake, 6-8 parts of apatite powder, 6-8 parts of kaolinite, 4-5 parts of trehalose and 4-5 parts of a natural surfactant. The preparation method includes: (1) mixing the fruit residue, bagasse, apatite powder and kaolinite uniformly, and adding a complex inoculant A for fermentation to obtain a fermentation product A; (2) mixing the livestock and poultry excrement, crop straw,soybean meal and rapeseed oil cake evenly, and adding a complex inoculant B for fermentation to obtain a fermentation product B; and (3) mixing the fermentation product A and the fermentation productB uniformly, performing airtight fermentation, then conducting high-temperature steam treatment, performing cooling to room temperature, adding trehalose and the natural surfactant, and blending the substances evenly to obtain the organic fertilizer. The organic fertilizer provided by the invention has high nutrient absorption and conversion rate, and can effectively improve the yield and qualityof vegetables.