As　a　key　transmission　component　in　computer　numerical　control　(CNC)　machine　tools,the　ball　screw　mechanism　(BSM)　is　usually　investigated　under　working　load　conditions.　Its　accuracy　degradation　process　is　relatively　long,which　is　not　conducive　to　the　design　and　development　of　new　products.　In　this　paper,the　normal　wear　depth　of　the　BSM　nut　raceway　is　calculated　under　the　variable　speed　operation　condition　using　the　fractal　wear　analysis　method　and　the　BSM’s　accelerated　degradation　proportional　wear　model.　Parameters　of　the　acceleration　degradation　model　of　the　double-nut　preloaded　ball　screw　pair　are　calculated　based　on　the　physical　simulation　results.　The　accelerated　degradation　test　platform　of　the　BSM　is　designed　and　manufactured　to　calculate　the　raceway　wear　model　when　the　lubrication　condition　is　broken　under　the　variable-speed　inertial　load　and　the　boundary　lubrication　condition　under　the　uniform　speed　state.　Three　load　forces　and　two　samples　are　selected　for　the　accelerated　degradation　test　of　the　BSM.　The　measured　friction　torque　of　the　BSM　is　employed　as　the　evaluation　index　of　the　accuracy　degradation　test.　In　addition,the　life　cycle　of　the　accuracy　retention　is　accurately　calculated　by　employing　the　parameters　of　the　physical　simulation　model　of　the　BSM.　The　calculations　mentioned　above　can　be　used　to　estimate　BSM’s　accuracy　performance　degradation　law　under　normal　operating　conditions.　The　application　of　the　proposed　model　provides　a　new　research　method　for　researching　the　precision　retention　of　the　BSM.　©　2023　Inst.　of　Scientific　and　Technical　Information　of　China.　All　rights　reserved.