The invention discloses a special multi-element pasty leaf fertilizer additive added with leather collagen hydrolysate for a pear tree. The collagen hydrolysate rich in nitrogen is extracted from leather scraps through a series of processes, the nutritional ingredient of a leaf fertilizer prepared from the collagen hydrolysate is slowly released, the release speed relatively fits with the nutrient needed in the growth cycle of a plant, so that the labor force is reduced on a certain degree, the fertilizer efficiency of the leaf fertilizer is higher than that of a mineral fertilizer, and with the addition of microelements like ammonium molybdate and magnesium sulfate, the special multi-element pasty leaf fertilizer additive meets the application requirements of stability, viscosity and adhesive force of the leaf fertilizer, slowly releases the fertilizer effect by rapidly penetrating through a surface film of the plant, and meets the growth requirements of the pear tree.