The problem of soil and water contamination caused by Cr discharged from dyeing, electroplating and metallurgical industries has become increasingly serious, which is a potentially great threat to the environment and public health. Therefore, it is essential to develop a quick, efficient and low-cost adsorbent for the remediation of Cr-contaminated wastewater. In this work, we successfully prepared MgAl-LDH/ commercial activated carbon nanocomposites (LDH-CAC) with hydrothermal. The effects of activated carbon type and loading on LDH-CAC were investigated. Moveover, we also have examined the adsorption capacity and adsorption behavior of LDH-CAC on Cr(VI), and proposed a potential removal mechanism. Lastly, the reusability of LDH-CAC was researched. The results showed that the prepared LDH-CAC@1 had the best removal performance at the commercial activated carbon type of CAC-103 and activated carbon loading of 1.0 g. The adsorption behavior study, on the other hand, indicated that LDH-CAC @1 could reach adsorption equilibrium within 10 min with a maximum adsorption capacity of 116.7 mg/g, which was significantly better than MgAl-LDH (10.7 mg/g) and CAC (21.3 mg/g). The primary removal mechanisms included adsorption-coupled reduction, ion exchange, surface precipitation, and electrostatic attraction. Reusability experiment revealed that the removal efficiency of LDH-CAC@1 decreased by 25.1% after four cycles, which illustrated the promising reusability of [email protected] study provides an effective adsorbent with a remarkably fast reaction, which has positive environmental significance for the treatment of Cr (VI) wastewater.