The invention discloses a formula feed for cattle and a preparation method thereof. The feed comprises the following raw materials: corn flour, sorghum, rice bran, alfalfa hay, distillers' grains, wheat bran, beet, corn stalks, cottonseed meal, soybean meal, calcium bicarbonate, salt, Chinese wild rye, rock flour, oil cakes of flax seed, sweet potatoes, cabbages, vitamin additives, mineral additives, amino acid additives, a rumen buffering regulating agent, enzyme preparations, a mould inhibitor and a traditional Chinese medicine additive. The preparation method comprises the steps of grinding, dosing, granulating and drying. The formula feed has the beneficial effects that the traditional Chinese medicine additive contained in the formula feed takes warming yang and tonifying the spleen and smoothing the intestine to remove stagnancy as the principles of treatment, has the functions of promoting blood circulation to remove blood stasis, removing food retention and promoting appetite and regulating qi and harmonizing blood, is used for treating constipation of cattle, can enhance the resistance of cattle, and has the advantages of good curative effects, specific functions and great effects, precision and appropriateness in medicine selection, super quality and low price, safety and applicability, no medicine residues, and the like when being used for treating constipation of cattle.