Incorporating silver (Ag) into the MoN coating, a synergistic lubrication system consisting of Ag, the Magnéli phase, and the AgMo xO y ternary was developed, which demonstrates exceptional friction control capabilities across a broad temperature range (25–650 °C). Therefore, the fabrication of MoWN-Ag composite coatings was achieved through magnetron sputtering, and the impact of varying Ag content gradients (0–20.9 at.%) on the mechanical properties and abrasion resistance of the coating was thoroughly examined. The results show that the hardness of the composite coating increases from 16.7 GPa to 21.2 GPa due to fine-grain reinforcement effects, and the wear rate at room temperature was optimized to 3.5 × 10 −7 mm 3/(N·m). Moreover, the combined lubricating effect of Ag precipitates and AgMo xO y significantly decreases the COF of the coating from 0.7 to 0.25 at elevated temperatures. Multi-step wear tests unveiled the progressive changes in phase composition and lubrication mechanism of the Ag-rich coating at 500 °C. It verified that Ag diffusion, along with the in-situ generation of AgMo xO y and MoO 3, is pivotal in diminishing the COF of the coating at elevated temperatures. These findings offer insights for the advancement of novel adaptive high-temperature lubricant coatings.