The invention relates to TMR fermentation ration containing citrus pulp for beef cattle and a preparation method of the TMR fermentation ration. The fermentation ration comprises the following components: semi-dehydrated citrus pulp, corn flour, distillers' grains, colza cake meal, precrushed straw, wheat bran, premixed aerobic fermentation materials, and an anaerobic fermenting agent. The preparation method comprises the following steps of uniformly mixing the semi-dehydrated citrus pulp, the corn flour, the distillers' grains, the colza cake meal, the wheat bran, and the premixed aerobic fermentation materials so as to obtain a mixture; putting the mixture in an open manner, and crushing the mixture so as to obtain a raw feed material; mixing and uniformly stirring the raw feed material, the pre-crushed straw and the anaerobic fermenting agent so as to obtain a new mixture, and adding water to the new mixture so as to obtain a feed; then pouring the feed in vacuum bags, vacuumizing the vacuum bags, sealing the feed and performing fermentation on the sealed feed for 20-30 days so as to obtain finished products. According to theTMR fermentation ration disclosed by the invention, the feed cost for the beef cattle is reduced, and besides, the food consumption of the beef cattle is increased. According to the preparation method disclosed by the invention, the problem that silage sources are short in the supply of the feed production of the beef cattle can be solved, and besides, ecological environment pollution caused by residues obtained by processing a great number of citruses is also avoided.