本文介绍了一种新型的圆度仪，它采用的位移传感器以全息柱面衍射光栅为标准器，动态范围宽，分辨率高，可进行圆度误差、波度及表面粗糙度的综合测量，比一般的圆度仪有更多的功能。本文介绍了传感器的原理、数字滤波、圆度误差的评定方法以及检定与实测结果． This paper introduces a new roundness meter, which uses the displacement sensor to holographic cylindrical diffraction grating as a standard instrument, wide dynamic range, high resolution, roundness error, waviness and surface roughness of the integrated measurement, More than the average circularity instrument has more features. This article describes the principle of the sensor, digital filtering, roundness error assessment method as well as verification and measurement results.