The form of principal spindle's dynamic errors is analysed firstly. Principal spindle's radial average errors and asynchronous errors, axial average errors and asynchronous errors, minimum radial separation center of some vertical machine center are all tested with SPN-300 of API. Three vertical machine centers are tested and every machine center is tested three times at different rotating speed. The test results and the influences of all errors are analysed at last.

The significance and present situation of machine tool's thermal characteristics test technology is expatiated first. Aiming at certain three-axis vertical machine center's mechanical principal spindle, thermal characteristics test is done when principal spindle's temperature is rise and fall. Spindle thermal error analyser is used to test machine center's thermal errors in X, Y and Z directions and monitoring temperture of spindle. The spindle's temperture and thermal errors are presented and the test results are analyzed at last. The machine center's thermal information are mastered through test data and analysed results.

Domestic CNC machine tool and NC machine tools abroad's main gap is accuracy stabilization rather than accuracy. Accuracy stabilization test is done on some three-axis vertical machining center aiming at the status. Laser interferometer is used to test X, Y, Z axis's positioning accuracy, repeat positioning accuracy and reverse gap. The test is done taking 80 days as the period. The accuracy test results is analyzed. From the positioning accuracy, repeat positioning accuracy and reverse gap curves we can see that, because of the factors of machine's use and temperature's change, X, Y, Z axis's positioning accuracy changes violently, repeat positioning accuracy and reverse gap change a little.

An analytical study on the component-level mechanical functional properties of the thermal structure connecting end frame was conducted, illustrating by advanced composite materials (ACM) C/C and C/SiC. Different grades of component-level experiments and analyses the weakness of composite connecting end frames were carried out, including the screw hole pull-out test, which mainly reflects the features of materials, the bending test of corner beams, and the corner box test with structural characteristics. The failure of different components and the factors have been obtained from this research.