利用波前传感器测量自由曲面镜片时，由于自由曲面镜片的直径通常大于波前传感器的接收孔径，主要采用子孔径拼接技术测量镜片的波前像差。针对子孔径拼接技术测量中存在着操作繁琐、数据处理量大等问题，提出渐进多焦点镜片波前像差的扩束测量方法，得到渐进多焦点镜片中央直径为22 mm圆形区域内的波前像差。为了验证试验的可靠性，将测量得到的波前像差泽尼克表述中的离焦项转换为球镜度，与条纹偏折法测量得到镜片的球镜度进行对比实验，实验结果证明了渐进多焦点镜片波前像差的扩束测量方法可以用于渐进多焦点镜片波前像差的检测。

In current measurement of the freeform spectacle lenses using wavefront sensor，the diameter of progressive addition lenses is usually larger than the receiving aperture of wavefront sensor, it is mainly used to measure the wavefront aberration of the lens by means of the sub-aperture stitching technique.In order to solve the problems of complicated operation and large amount of data processing in the measurement of the sub-aperture stitching technology,a method of beam expanding-shrinking system measurement for wavefront aberration of progressive addition lens was presented,through which the wavefront aberration within 22 mm diameter circular area of progressive addition lens could be got.In order to verify the reliability of the test,the measured defocus co-efficients in Zernike representation of wavefront aberration were transformed into spherical mirror degree,and compared with the spherical mirror degree measured by fringe deflection method. Results prove that the method based on the beam expanding-shrinking system is feasible.