The　theory　of　homogeneous　transfer　matrix　(HTM)　are　applied　in　establishing　the　kinematic　error　model　of　5-axis　NC　machining　tool　with　two-axis　turntable,　and　the　model　is　simplified.　A　method　of　kinematic　error　deviation　in　this　type　of　5-axis　NC　machining　tool　based　on　telescoping　double　ball　bar　is　developed　to　measure　the　kinematic　error.　Six　kinds　of　simultaneous　three-axis　control　motions　with　two　translational　axes　and　one　rotary　axis　are　designed　to　identify　the　deviations.　In　the　measurement,　telescoping　double　ball　bar　is　used　to　measure　the　relative　distance　between　the　spindle　and　the　worktable　in　the　motion　of　5-axis　NC　machining　tool.　Finally,　measured　value　of　telescoping　double　ball　bar　is　substituted　into　the　model　to　obtain　kinematic　error　of　5-axis　NC　machining　tool.　This　method　has　greatly　simplified　the　whole　process　of　calculation　of　mathematical　model　and　error　deviation.　From　the　simulation,　it　has　been　confirmed　that　the　proposed　method　gives　precision　results　and　is　able　to　apply　to　the　measurement　of　5-axis　machining　tool　effectively　and　conveniently.