双片零级波片和消色差波片是双片波片贴合的补偿器，双片波片中的光轴对准精确度影响波片的偏振调制。提出一种精密检测贴合式双片波片光轴偏差角的方法，该方法基于旋转补偿器的直通式椭偏系统，可在未知起偏器方位角和检偏器方位角相对关系的情况下，通过波片的连续旋转测量偏差角度。探讨了偏差角度对椭圆偏振测量的影响，具体描述了检测方法的原理及数学表达，并通过对检测过程的模拟验证了方法的有效性。此方法对检测和提高双波片式补偿器制造精度具有参考价值。

Zero order waveplates and achromatic waveplates are biplate compensators. The misalignment angle between the axes of the two waveplates affects the phase modulation of the designed compensator. A method for measuring the misalignment angle of the optical axes is reported. The method is based on a straight-through rotating-compensator system. The measurement can be implemented without the knowledge of the relative azimuthal angle between the polarizer and analyzer. The influence of the misalignment angle on the ellipsometric measurement is analyzed. The principle and mathematical expressions are given. The validation of this method is demonstrated by the simulation of measurement process. This method is valuable for inspecting and hence for improving the accuracy of biplate compensator in manufacturing.