A novel kind of diamond-TiC-Ti gradient interlayer has been successfully obtained between self-standing diamond and Ag/Cu films by combining Ti ion implanted into the achieved CVD diamond films by MEVVA with depositing Ti layer and by magnetron sputtering and annealing in vacuum. In the metallization system, RF sputtering was also utilized to deposit Ag/Cu films consistent with target composition based on orthogonal experimental design. Transition from Ti to Ag/Cu could be controlled to distribute gradually through adjusting both of their deposition powers. X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) results show TiC is formed and the content of Ti increases gradually in diamond and decreases in the sputtering depth profiles of the Ti-Ag/Cu film. Raman spectroscopy indicates the effects of Ti ion implantation on the structure of diamond. Gradient design leads to order-of-magnitude improvements in adhesion between diamond and Ag/Cu films, which can be a good choice for heat sink.