According to the problems of adjusted calibration level, difficult attitude regulation, low positioning accuracy and efficiency about aircraft mass center measurement, a kind of multi-axial mobile flexible support structure was designed. On this basis, the method of measurement attitude adjustment based on flexible support structure was proposed. Flexible support structure was designed in detail. The process of automation adjusted attitude measurement was realized combining with ranging sensor, pressure detection and servo motion control etc. Positioning accuracy of the flexible support structure was measured by experiment system. The results show that positioning accuracy reaches ±0.2 mm of X,Y,Z axis,the attitude regulation system of using flexible support structure is stable, reliable and high efficient.