The invention discloses a fast ion conductor modified lithium ion battery anode material lithium cobalt oxide comprising lithium cobalt oxide and a lithium fast ion conductor layer coating the outer surface of the lithium cobalt oxide. The lithium fast ion conductor layer comprises the components of Li1+x+yAxB2-xSiyP3-yO12-eN, wherein A is one or more than one of Al, Sc, La, Cr, Fe, Tl, Eu and In, B is one or more than one of Ti, Zr and Hf, N is one or more than one of Li2O, MgO and Y2O3, and x, y and e are all not less than 0 and not more than 2. The preparation method of the fast ion conductor modified lithium ion battery anode material lithium cobalt oxide comprises the following steps of: evenly mixing A, B an N sources, lithium salt, a silicon source, a phosphorus source and a lithium ion battery anode material to be modified, carrying out the processes of drying, roasting, crushing, screening and the like to prepare the lithium ion battery anode material coated with a phosphate system on the surface. The modified anode material lithium cobalt oxide not only can work under a higher voltage and greatly improve the battery capacity, but also greatly improves the cycle performance, the multiplying power performance, the overcharging performance and the safety performance thereof.