Modified biochar-like adsorbent material BC@MnAl-LDHs was prepared by carbonation and co-precipitation method using sugarcane bagasse fibre as raw material. The effects of the dosages(0.5, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 g/L), initial pH of the solution(3, 4, 5, 6, 7, 8), initial pollutant mass concentrations(5, 10, 20, 40, 60, 80, 100 mg/L), temperatures(298, 303, 308, 313 K) and adsorption reaction times(2, 15, 60, 120, 180, 240, 480, 600, 720 min) on the adsorption of Cr(Ⅵ) were analyzed by static experiments. The X-ray diffraction(XRD), scanning electron microscopy(X-ray diffraction(XRD), scanning electron microscopy(SEM), fourier transform infrared spectroscopy(FTIR) and specific surface area and porosity analysis(BET) were used to characterize and analyze BC@MnAl-LDHs before and after adsorption of Cr(Ⅵ), as well as to analyze the adsorption mechanism. The results showed that when the dosage of BC@MnAl-LDHs was 2.0 g/L, the initial mass concentration of Cr(Ⅵ) was 10 mg/L, and the pH was 3, the removal rate of Cr(Ⅵ) could reach more than 95%. The modification improved the removal efficiency of bagasse activated carbon for Cr(Ⅵ). The adsorption isotherm of Cr(VI) by BC@MnAl-LDHs was more in line with the Freundlich adsorption model. The saturated adsorption amount of 56.42 mg/g was obtained by fitting the Langmuir model at 313 K, which was in line with the proposed second-order kinetic model, and the adsorption process was a multimolecular-layer, spontaneous, and heat-absorbing chemisorption process. BC@MnAl-LDHs containing abundant oxygen-containing functional groups contributed to its removal of Cr(Ⅵ), and the adsorption of Cr(Ⅵ) by BC@MnAl-LDHs mainly included redox, ion exchange and electrostatic adsorption.