In this study, a composite of activated boron nitride modified with 5% polyaniline (a-BN@5%Pani) was synthesized by in situ chemical oxidation. The physicochemical properties of the a-BN@5%Pani before and after adsorption were investigated using various analytical techniques (e.g., SEM, FTIR, BET, XPS). The results showed that the surface charge of the modified composite adsorbent was enhanced, and the maximum adsorption of Cr(Ⅵ) and Cu^2+ by a-BN@5%Pani were 589.32 mg/g and 185.30 mg/g, respectively. Kinetic studies showed that the adsorption process was dominated by chemical adsorption, and the adsorption rate was fast, reaching adsorption equilibrium at about 30 min. Cr(Ⅵ) adsorption in the coexisting system was 4~5 times higher than Cu^2+ adsorption, demonstrating its selective adsorption of Cr(Ⅵ). Furtherore, there was no significant loss of adsorption efficiency after five cycles of regeneration , and the removall efficiency could reach about 80%. This study provides new adsorption materials for adsorption recovery of Cr(Ⅵ)