The invention relates to a lithium manganese coating process applied to an anode material for a lithium ion battery, and in particular relates to a lithium manganese liquid-phase coating process. The lithium manganese liquid-phase coating process comprises the following steps: firstly washing lithium manganese, adding water to prepare into lithium manganese suspension liquid, and then preparing a mixed alkali solution of lithium hydroxide and ammonia water; preparing an aluminum nitrate solution; adding the mixed alkali solution of the lithium hydroxide and the ammonia water and the aluminum nitrate solution into the lithium manganese suspension liquid simultaneously in a stirring state; after the completion of dropwise adding, spray drying the solution; roasting a mixture obtained by spray drying, wherein the roasting temperature is 700-900 DEG C and the time is 9-11 hours, and then cooling along with a furnace; after cooling, sieving by using a 200-mesh standard sieve, and then grinding by using a Chinese herbal medicine pulverizer to obtain an aluminum-coated lithium manganese finished product. The lithium manganese liquid-phase coating process is easy and uniform in coating, and can significantly reduce the contact area between the lithium manganese and electrolyte, reduce the dissolution of a manganese element in the electrolyte, and improve the cycle performance and high-temperature performance.