The　traditional　reliability　evaluation　of　the　bearings　of　machine　tool　is　not　related　to　the　condition　characteristics　of　the　using　process.　A　condition　maintenance　decision　utilization　of　condition-based　maintenance　was　proposed.　First,　operation　condition　information　of　the　bearings　was　obtained　by　the　senor,　such　as　the　acceleration　senor.　Then,　the　condition　characteristics　of　the　root　mean　square　and　frequency　center　were　extracted,　Weibull　proportional　hazard　model　(WPHM)　was　also　establish,　which　regarded　Weibull　distribution　as　failure　rate　function.　Then,　combined　with　the　lifetime　data　of　similar　parts,　three　parameters　were　estimated　through　Newton-Raphson　method.　Finally,　a　maintenance　decision　model　based　on　WPHM　was　established.　Using　the　similar　type　of　parts　lifetime　data　to　determine　the　maintenance　failure　threshold,　according　to　failure　threshold,　maintenance　decision　can　be　conducted.　Results　show　that　this　maintenance　decision　model　can　improve　the　availability　of　the　bearings　greatly,　and　make　full　use　of　the　effective　life　of　the　machine　tools.　©　2016,　Editorial　Department　of　Journal　of　Beijing　University　of　Technology.　All　right　reserved.