The invention discloses a special compounded water-soluble fertilizer for acidic soil and belongs to the technical field of agricultural chemical fertilizers. The special compounded water-soluble fertilizer for the acidic soil, disclosed by the invention, is prepared from urea, dopamine, a bacillus pasteurii bacterial solution, a homemade emulsion, inorganic salts, additives, a carbomer solution,a chitosan solution, kitchen waste fermentation liquor, poultry manure decomposed liquor and water. During preparation, the special compounded water-soluble fertilizer for the acidic soil is preparedthrough firstly, subjecting the urea, the dopamine, the homemade emulsion, the inorganic salts and the water to stirring and mixing, then, sequentially adding the carbomer solution, the chitosan solution, the kitchen waste fermentation liquor and the poultry manure decomposed liquor, adjusting pH, continuing to carry out stirring and mixing, then, carrying out sterilizing so as to obtain a sterilized mixed solution, subjecting the bacillus pasteurii bacterial solution and the additives to stirring and mixing, then, adding the sterilized mixed solution into the mixture, introducing argon gas into the sterilized mixed solution, and carrying out discharging. According to the special compounded water-soluble fertilizer for the acidic soil, disclosed by the invention, the utilization ratio of nutritional ingredients and effective ingredients can be effectively increased, the increase of yield of plants can be promoted, and the quality of fruits of the plants can be improved.