Abstract: Three main methods for surface modification of synthetic diamond are reviewed. The first one is metallization of diamond surface, such as physical or chemical vapor deposition, electroless plating, electroplating, vacuum micro-evaporation, salt bath plating, etc. The treated diamonds are mainly used in diamond tools and electronic packaging materials. The second one is the treatment of coupling agent or surfactant, which improves the interfacial properties between diamond and organic system. The technology is applied in diamond powder dispersion and resin grinding wheels. The last one is the functionalization of diamond film and nano diamonds, which is applied on materials used in industries such as electrochemistry, biosensors, electrodes and so on. The essay provides reference for the research and application of diamond surface modification.