A TiC coating was rapidly formed on the surface of diamond particles by thermal explosion reaction using Ti/Carbon black/PTFE/Diamond powders as raw material. XRD and SEM were used to analyze and observe the phase composition and microstructure of the coating. Results show that the phase composition of bonders was TiC, Ti, and TiF3 after thermal explosion reaction. The diamond surface obtained after the reaction can achieve good coating. Changing the diamond content in the raw material can regulate the phase composition of the coating. The coating on the diamond surface was mainly composed of TiC. When the diamond content in the raw materials was 20-40%, the coating was composed of TiC and TiF3. When the diamond content in the raw material was 60-80%, the coating was composed of TiC and Ti.