The　high　reliability　and　extended　life　of　seawater　hydraulic　components　is　dependent　on　the　tribological　properties　of　key　friction　pairs,　more　and　more　attention　has　been　given　to　the　performance　degradation　and　lifetime　of　the　friction　pairs.　In　this　paper,　the　wear　process　of　Tungsten　carbide　(WC)　with　6%wt　of　Ni　(WC-6Ni)/SiC　friction　pair　is　studied　through　the　tribological　test　under　seawater　lubrication.　Considering　the　random　effects　and　the　complex　wear　mechanism　of　WC-6Ni/SiC,　an　efficient　Inverse　Gaussian　(IG)　process　supported　lifetime　prediction　model　is　established　by　coupling　the　multiple　stresses　under　seawater　lubrication,　and　the　parameters　in　the　proposed　IG　process　model　are　derived.　Two　actual　cases　are　used　to　validate　the　proposed　method.　The　prediction　model　and　experimental　results　show　the　high　accuracy　in　time-varying　life-time　prediction　of　WC-6Ni/SiC,　which　is　of　great　significance　to　the　evaluation　of　friction　pair　and　the　main-tenance　for　seawater　hydraulic　components.