Abstract: Carbon-based carbon (CDC) has been widely used in gas storage and tribology due to its unique characteristics.The preparation of CDC coating by chlorine etching has the advantages of simple operation, low cost and easy control.The influence of the heat treatment atmosphere on the properties of CDC coating was studied systematically, and the relationship between the properties of CDC coating andheat treatment atmosphere was analyzed by means of laser confocal microscope, high−temperature friction and wear testing machine, microhardness tester and scratch tester.The results showed that the CDC coating prepared at 1175 ℃ for 2 h with 5%—9% chlorine content had a smooth surface, high hardness and good bonding strength with the substrate.The dry friction coefficient of CDC coating is 0.108, with the best wear resistance and good tribological properties.The microhardness of CDC coating is about 153 HV, which is significantly lower than that of SiC ceramics.