Abstract: For it is difficult to deal with automatic segmentation of noisy weak edge radiography image with traditional Chan-Vese(C-V) algorithm, a new image segmentation algorithm for radiography based on the level set model has been explored. This algorithm uses the segmentation of C-V algorithm as the initial contours, and then constructs a speed function with both local information of active contour and global information of C-V method. It is proved that this model is robust to initial contours’ positions and can segment noisy weak edge radiography image automatically. Besides, the testing for segmentation of the image with slender topological structure and tiny inner hole shows its significant effect.