A test method of rotor space bending axis was put forward. Firstly

for a practical bended rotor

the bending of each section centroid relative to the rotation center can be obtained by using the eddy current displacement sensors

and the bending degree of different sections of the rotor can be obtained in the same absolute coordinate system. Secondly

the cubic spline function was applied to fit the space geometry center line of rotor

and the threedimensional solid models of the bended rotor were shown by using the OPENGL graphics function

which was called by the Visual C++. Finally

the traditional means of measurement based on the dial indicator were employed to verify the proposed method. The results indicated that

the shaft orbit of each section except for section 1 and section 6 measured by the proposed method were consistent with the shaft orbit of the dial indicator

and circle fitting results were also basically coincident. Whats more

the error range of the circle fitting of section 1 and section 6 were in reasonable agreement. Thus the method is available to investigate the migration.