Abstract: To further improve the quality of the diamond coatings deposited on diamond-particles-impregnated cemented carbide substrate, a pretreatment method of pre-fixing seeds is proposed. The substrate is attached with titanium powder and then seeded, and finally pre-fixed by microwave. The quality and bonding performance of the diamond film prepared by this method and the original conventional method are compared with SEM, Raman spectroscopy, and indentation experiments. The results show that after the pretreatment method of pre-fixing seeds, the diamond nucleation density at low temperature is about 1.5 times higher than that of the coating after conventional pretreatment, and that the uniformity and flatness of the coating are significantly improved. It can be seen that the purity index and crystallinity index of diamond have been improved about 30% and the internal stress of the coating has been decreased by 50% through the analysis with Raman spectroscopy. The indentation comparison experiment confirms that the bonding strength has been improved to a certain extent.