Abstract: In recent years, nano zero-valent iron (nZVI) has been used to remove Cr(Ⅵ) because of its large specific surface area, strong reducing power, and low cost. However, due to the high surface energy and inherent magnetic force, nZVI particles are prone to conglomerate, easily oxidize, and become unstable in air, limiting their applications. In view of this, this review paper focuses on modified nZVI with carbon materials as supporting platforms, comparison of carbon-based nZVI composite preparation methods, reaction efficiency analysis of different carbon-based nZVI composites for Cr(Ⅵ) removal, and the factors affecting Cr(Ⅵ) removal by the composite materials. The results show that: (1) The composite synthesized by wet chemistry method is beneficial for enhancing nZVI dispersion and reducing conglomeration. Also, the composite synthesized by the thermal conversion method helps save cost and improve the binding property of carbon materials and nZVI. (2) Generally, different carbon materials loaded with nZVI can effectively improve the dispersion, stability, and oxidation resistance of the nZVI. (3) Carbon-based materials embedded with nZVI can significantly reduce the adverse effects of environmental factors on nZVI. (4) Carbon-based nZVI composites can enhance the removal capacity of Cr(Ⅵ), and the maximum adsorption capacity of Cr(Ⅵ) is 1.2-20 times higher than that of nZVI. This review is intended to provide the synthesis methods of carbon-based nZVI composites. And it is to improve the properties of carbon-based nZVI composites. It is expected to provide some enlightenment for the development of efficient and stable carbon-based nZVI composites to repair Cr(Ⅵ) in the environment.