The invention belongs to the technical field of pet foods, and provides a chocolate-flavored yeast source pet nutrient solution and a preparation method thereof. The chocolate-flavored yeast source pet nutrient solution comprises the following components in parts by weight of 68.9-87.9 parts of water, 3-7 parts of enzymolysis chicken liver meal, 2-5 parts of enzymolysis chicken meat, 2-5 parts ofgoat milk powder, 1-3 parts of a thickening agent, 0.5-2.5 parts of taurine, 0.8-2.0 parts of calcium carbonate, 1 part of a compound premix, 0.5-2 parts of composite glue, 0.3-0.8 part of lecithin, 0.2-0.5 part of a yolk extract, 0.2-0.6 part of yeast beta-1, 3/1, 6-glucan, 0.2-0.6 part of mannan oligosaccharides, 0.2-0.6 part of rapeseed oil, 0.2-0.5 part of sodium tripolyphosphate and 0.1-0.3 part of monostearin. Through the technical scheme, the problems that in the prior art, pet nutrient supplementing products are poor in palatability and are poor in effects on improvement of the immunity of pets, and improving health of intestines of pets, are solved.