Abstract: To tackle the difficulty in measuring complex enclosed inner cavity in industry,a geometric measurement method integrating industrial CT(Computed Tomography) and C-V model is presented.In this method,C-V model is used to extract ordered chain of target edge coordinates.And then,Green theorem and Euclidean distance formula are applied to compute the area and perimeter of target region.To extract target edges in C-V model,the prior knowledge of edge grey intensity is used to improve the accuracy of measurement in this paper.For computing the area and perimeter of the target region,ordered coordinates of the target edges are selected reasonably and interpolation of the ordered coordinates is done,which further improves the accuracy of measurement.The experiment results show that,compared to the measurement method with 2D Facet model,the accuracy with improved measurement method increases about one order of magnitude.Besides,improved measurement method has been used in engineering.