A　unique　method　based　on　reactions　between　WC　and　Co-W-C　phases　was　developed　for　controllable　precipitation　of　W2C/W　in　thermal　sprayed　WC-Co　coatings.　With　the　increase　in　amount　of　the　ultrafine　precipitates,　it　is　surprising　to　find　that　the　wear　rate　of　the　prepared　WC-based　coatings　drastically　decreased　by　nearly　6　times　before　an　obvious　rise,　and　the　wear　mechanism　gradually　changes　from　abrasive　wear　in　a　ploughing　mode　to　brittle　fracture　at　surface　microcracks　because　of　the　reduction　in　plasticity　and　fracture　toughness.　FEM　modeling　results　indicate　that　inhomogeneous　W2C　distribution　is　more　likely　to　cause　localized　stress　concentration　of　coating,　especially　at　the　Co　binder　around　which　there　are　few　W2C　particles.　Instead,　an　appropriate　amount　of　evenly　dispersed　W2C　can　act　as　transitional　sites　to　reduce　the　shear　stress　gradient　between　WC　and　Co　binder,　thus　decreasing　the　plastic　deformation,　fatigue　fracture　and　ploughing　wear　of　the　cermet　coating.