随着军转民的逐渐深入，大中型国有企业开发的民品越来越大，越来越杂，接触各种大圆弧的机会越来越多。鉴于目前许多企业又没有三座标测量机，对大圆弧的测量存在一些困难，本文介绍一种比较实用可行的方法。 大圆弧：指较大直径的圆周的一部分，超出了万能工具显微镜的测量范 With the gradual deepening of the military transition to civilian life, the civilian products developed by large and medium-sized state-owned enterprises are becoming more and more numerous and complex. There are more and more opportunities to contact various large arcs. In view of the fact that many enterprises currently do not have a CMM, there are some difficulties in measuring large arcs. This article presents a practical and feasible method. Large arc: refers to the larger part of the circumference of the circle, beyond the universal tool microscope measurement range