Abstract: Using the waste cigarette leave powder residue as raw materials, after carbonization, the amino functional group was introduced to prepare the ammoniated tobacco leave powder residue biochar (NH ₂/TPB), and the effects of pH, dosage, temperature and adsorption time on NH ₂/TPB adsorption of Cr(Ⅵ) were studied. The mechanism was analyzed by scanning electron microscopy (SEM), Fourier infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and other techniques. The results show that when the initial concentration is 210 mg/L, pH=4, dosage is 0.8 g/L, temperature is 45℃, and adsorption time is 120 min, the maximum adsorption capacity of NH ₂/TPB for Cr(Ⅵ) is 103.627 mg/g. The adsorption process conforms the quasi-second-order kinetic model and Langmuir adsorption isotherm model. The adsorption and removal mechanism of Cr(Ⅵ) mainly include electrostatic interaction, reduction reaction, coordination and complexation with —NH ₂, —OH, —COOH, and “π-π” interaction with Si—O—Si. Through five times about adsorption-desorption tests, the Cr(Ⅵ) removal rate is more than 82.88%. This research presents that the ammoniated tobacco leave powder residue biochar has the potential to treat and repair acidic Cr(Ⅵ)-containing wastewater pollution.