In recent years, the Intelligent Transportation System (ITS) has attracted growing attention from experts and scholars. Edge-based traffic sign image segmentation is a key technology in the field of traffic sign recognition. Therefore, traffic sign edge detection technology is of vital importance. Edge detection is an image processing technology, which can quickly and accurately extract image edge information. Thus, improving the accuracy of edge detection has become a significant research direction. Furthermore, due to the influence of the complexity of external factors on actual images, the conventional edge detection algorithms present insufficient adaptability, so the improved performance of the operators needs to be further investigated. This paper mainly studies several traditional edge detection techniques and applies them to traffic sign maps using MATLAB. After comparing the results, we proposed an improved Canny algorithm and analyzes its applicability in traffic sign edge detection under different external interference factors.