In the present work, WS₂–MoS₂ nanocomposite films were sputtered, based on which solid/liquid-lubrication systems were realized by combining the WS₂–MoS₂ films with space oils including MACs (multialkylated cyclopentanes) and CPSO (chlorinated-phenyl with methyl-terminated silicone oil). The tribological behaviors of the solid/liquid systems were investigated in vacuum. It was revealed that in comparison to pure WS₂ film, the WS₂–MoS₂ composite film exhibited an enhanced tribological performance. Moreover, our results identified that the WS₂–MoS₂/MACs system integrated better the advantages of the solid and liquid lubrications and thereby a synergistic lubricating effect was generated. A tribological model was established to explain the synergistic lubricating mechanism.