The invention discloses a preparation method of a ZnCo2O4 nano-plate serving as a lithium ion battery negative electrode material. The preparation method comprises the steps of carrying out basic hydrolysis on zinc salt and cobalt salt according to the molar ratio of 1 to 2 in a hydrophilic solvent by virtue of an alkaline reagent under the microwave irradiation induction to generate a metal hydroxide or hydrocarbon precursor, and then carrying out low-temperature heat treatment to obtain a two-dimensional ultrathin ZnCo2O4 nano-plate to be used as the lithium ion battery negative electrode material finally. With the adoption of the preparation method, as the ZnCo2O4 nano-plate serving as the lithium ion battery negative electrode material is synthesized with the assistance of microwaves, the preparation process is simple, the cost is low, the reaction condition is mild, special equipment is not needed in the whole reaction process, the quality of the product which is finally obtained is high, and the morphology and the size of the product are uniform; when being used as the lithium ion battery negative electrode material, the ZnCo2O4 nano-plate shows good electrochemical performance, can be used for well solving the problems of serious capacity fading, stable long-term circulation and low rate performance of the transition metal oxides and is an ideal lithium ion battery negative electrode material which has wide commercial application prospect.