Abstract Aramid nanofibers/Bacterial cellulose (ANFs/BC) nanocomposite aerogels have been successfully synthesized via a facile process. Benefiting from the hydrophilicity and negative charge on the surface, the aerogels could selectively adsorb cationic dye in effluent. Compared with slight adsorption of anionic dye methyl orange (MO), the aerogels exhibited high adsorption efficiency for cationic dye methylene blue (MB). The effect of aerogels synthesized by different mass ratios of BC and ANFs on the adsorption efficiency of MB were studied. The dyes removal efficiency (R%) towards MB was 98.8%, which was obviously higher than that of pristine BC aerogels (27.9%). The adsorption kinetic parameters suggested that it fitted the pseudo-second-order model (R2 > 0.99) well and the adsorption process followed the Langmuir model. Besides, the effect of diverse experimental conditions such as adsorption time and initial dyes concentration on the adsorption performance of aerogels was also investigated, the adsorption capacity of aerogels could reach 54.27 mg/g. Consequently, the excellent selective adsorption of ANFs/BC nanocomposite aerogels may exhibit a promising application in effluent treatment.