The invention discloses a preparation method of a terbium-doped lithium manganate material for a lithium ion battery. The method comprises the following steps: (a) weighing lithium carbonate, manganese oxide and terbium oxide according to a stoichiometric ratio; (b) adding anhydrous ethanol into the raw materials weighed in the step a, carrying out ball milling, then taking out the product and drying to obtain a terbium-doped lithium manganate raw material; (c) adding acetate fiber and mixed molten salt of potassium chloride and sodium chloride into the terbium-doped lithium manganate raw material obtained in the step b, adding the anhydrous ethanol into the obtained mixture, carrying out ball milling and then drying; (d) sintering the raw material treated in the step c, cooling after sintering, washing the obtained powder with water, and drying to obtain the terbium-doped lithium manganate material. The terbium-doped lithium manganate material for the lithium ion battery has higher discharge capacity; the terbium-doped lithium manganate material has a hollow tubular structure and is loose in tube wall, thus relieving the problem of volume expansion caused in charging and discharging processes; the stability of the terbium-doped lithium manganate material is improved by using inorganic filler titanium dioxide in the acetate fiber.