In this research, we have prepared a new type of multistage aperture nitrogen-doped carbon materials [CN-x, (x = 600, 700, 800, 900, 1000)] by one-step carbonization at different calcination temperatures. The structure of the CN-x is characterized by X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, Brunauer-Emmett-Teller, Scanning electron microscopy, and Raman spectroscopy. The effects of pore structure, nitrogen morphology, and defects on the adsorption properties are analyzed. We have also studied the desulfurization activity of CN-x for dibenzothiophene (DBT). Experimental data show that CN-900 has very good adsorption desulfurization activity, exhibiting a theoretical Langmuir adsorption capacity of up to 37.28 mg/g. When the DBT concentration is 100 ppm, CN-900 reaches a DBT removal rate of over 99%. The effects of calcination temperature and nitrogen content on the adsorption properties of the CN-x are examined. The experimental results show that the nitrogen content is positively correlated with the adsorption performance. The cheap and readily available D-(+)-glucosamine hydrochloride is used as the precursor of the CN-x, and the adsorbent prepared by a simple one-step carbonization method has good application prospects in the desulfurization process.