The invention discloses a preparation method of a large-layer-spacing graphite anode material of a sodium-ion battery. The preparation method comprises the following steps of: (1) dissolving a proper amount of carbon source into a solvent, then adding graphite oxide, and after stirring at a rotating speed of 10 to 50rpm to uniformly mix the components, drying to obtain carbon source coated graphite oxide; and (2) placing the carbon source coated graphite oxide obtained in the step 1 into a quartz glass beaker, adding liquid nitrogen, then rapidly placing the quartz glass beaker into a microwave reactor, performing a reaction for 5 to 20 minutes under the microwave power of 250 to 1,000W, and after completely volatilizing the liquid nitrogen, standing for 5 minutes and taking out the product so as to obtain the large-layer-spacing graphite anode material, wherein the quantity of the liquid nitrogen is subject to soaking on the carbon source coated graphite oxide. Compared with conventional graphite and commonly coated and reduced graphite anode, the prepared graphite anode material has the advantages of large layer spacing, high sodium storage capacity, large coulombic efficiency and long cycle life, and meets the requirements of the high-performance sodium-ion battery for comprehensive performance of the anode material.