The invention discloses a spherical filter material for removing nitrogen oxides, and relates to an air filter box and oral-nasal mask formed by the spherical filter material. The method comprises thefollowing steps: (a) uniformly mixing bentonite, activated carbon, a zeolite molecular sieve and an auxiliary agent to obtain a mixture, wherein the weight ratio of the bentonite to the activated carbon to the zeolite molecular sieve to the auxiliary agent is (150-250):(20-100):(180-300):(5-40); and (b) under conditions of adding water to the mixture raw material obtained in the step (a) for wetting, rolling the wet raw material into balls through a pelletizer, and then performing drying and sintering for solidfication to form the spherical filter material with certain strength and adsorptionperformance. According to the invention, under the synergistic effects of the above raw materials, the special pelletizing process is used, so that the prepared spherical filter material has a high removing rate of the nitrogen oxides in the air; and when the filter material is used for the oral-nasal mask, the obtained oral-nasal mask has strong adsorption performance and good air permeability.