The　machining　accuracy　is　an　important　index　to　evaluate　the　machine　tool　characteristics,　and　error　measurement　and　compensation　are　effective　methods　to　improve　the　machining　accuracy　with　low　cost.　Error　measurement　is　a　prerequisite　and　basis　for　error　compensation,　so　how　to　quickly　and　accurately　measure　the　machine　error　is　particularly　important.　To　quickly　and　accurately　detect　the　geometric　error　of　multi-axis　NC　machine　tool,　a　new　method　with　laser　tracker　based　on　the　sequential　multi-lateration　measurement　principle　is　proposed　in　the　paper.　The　laser　tracker　is　used　to　measure　the　same　motion　trajectory　of　the　linear　axis　and　rotary　axis　of　machine　tool　at　different　base　stations.　Based　on　the　GPS　principle,　the　space　coordinates　of　each　measuring　point　can　be　determined　by　large　amount　of　measured　data.　Then　according　to　the　error　model　of　the　linear　axis　and　rotary　axis,　each　error　can　be　separated.　In　the　paper,　the　principles　of　sequential　multi-lateration　measurement　are　analyzed　in　depth.　By　establishing　the　mathematical　model　of　sequential　multi-lateration　measurement　for　the　linear　axis　and　rotary　axis,　the　algorithms　for　linear　axis　measurement　and　rotary　axis　measurement　are　derived　and　proved　feasible　by　simulations,　respectively.　Meanwhile,　the　error　separation　algorithm　is　also　deduced.　The　results　of　experiments　show　that　this　method　can　achieve　quick　and　accurate　detection　of　errors　in　multi-axis　NC　machine　tool.