The invention discloses a preparation method of nitrogen content-adjustable nitrogen-doped ordered mesoporous carbon. The preparation method comprises the following steps dissolving a mixture of a nitrogen-containing compound and inorganic base in a formaldehyde solution, adding m-dihydroxybenzene with stirring, and stirring for reacting; adding the prepared mixed solution into F127 dissolved in amixed solvent of ethanol and water, adding hydrochloric acid for catalyzing a reaction, and stirring continually for 0.5 to 4 hours; aging the mixed solution at room temperature after finishing the stirring, pouring out supernatant, and drying to obtain a sample; controlling the heating rate of a tube furnace under the protection of nitrogen gas, carbonizing the prepared sample to obtain the nitrogen-doped ordered mesoporous carbon. The method has the characteristics of mild reaction condition, short reaction time, simple process, and adjustable and controllable nitrogen doping content and the like, and is more suitable for producing the nitrogen-doped ordered mesoporous carbon on a large scale.