Instead　improving　the　accuracy　of　machine　tool　by　increasing　the　precision　of　key　components　level　blindly　in　the　production　process,　the　method　of　combination　of　SNR　quality　loss　function　and　machine　tool　geometric　error　correlation　analysis　to　optimize　five-axis　machine　tool　geometric　errors　will　be　adopted.　Firstly,　the　homogeneous　transformation　matrix　method　will　be　used　to　build　five-axis　machine　tool　geometric　error　modeling.　Secondly,　the　SNR　quality　loss　function　will　be　used　for　cost　modeling.　And　then,　machine　tool　accuracy　optimal　objective　function　will　be　established　based　on　the　correlation　analysis.　Finally,　ISIGHT　combined　with　MATLAB　will　be　applied　to　optimize　each　error.　The　results　show　that　this　method　is　reasonable　and　appropriate　to　relax　the　range　of　tolerance　values,　so　as　to　reduce　the　manufacturing　cost　of　machine　tools.