The invention discloses a feed additive of a high productive dairy cow. The feed additive comprises the following components of 40-55 percent of extruded soybean, 10-15 percent of hawthorn fruit powder, 5-10 percent of urea, 2-6 percent of rumen-protected lysine, 1-2 percent of rumen protected methionine, 2-6 percent of baking soda, 10-15 percent of monensin, 3-8 percent of slow release preparation and a 0.05-0.1 percent of nicotinic acid. The slow release preparation comprises ferrous sulfate, copper sulfate, calcium carbonate, manganese sulfate, zinc sulfate and sodium metabisulfite. The feed additive of the high productive dairy cow is matched with a cow daily ration for feeding the cow, and thus enough nutrition storage can be provided for the perinatal period of the cow, enough nutrition supply is provided for the lactation peak time, the energy negative balance and physical body condition loss of the cow in the lactation peak time are made up, and the daily milk production and peak sustaining force are increased.