Effects of carbide content on the mechanical and tribological properties of DLC/Cr3C2–NiCr duplex coatings were systematically investigated. Results revealed that cermet coating with high carbide content provided strong support for the top DLC film by bearing most of the contact stress, thus improving its hardness, load-bearing capacity, and adhesion strength. The increased carbide content increased the contact and shear stresses on duplex coating during the friction process, intensifying the graphitization of the top DLC film but inhibiting the formation of a graphitized transfer film on the counterpart, thus slightly increasing its friction coefficient. However, the predominant wear mechanism changed from high-efficiency abrasive wear to low-efficiency adhesive wear for low to high carbide content, superior wear resistance was thereby achieved.