Stereo image line feature extraction technology has also been rapid development, for the current line extraction technology review article is relatively small, and line feature extraction research methods are many, various methods are uneven, most researchers are difficult to have a more comprehensive grasp of the situation. In this paper, the line extraction technology of stereo image proposed by scholars at home and abroad is systematically summarized. And this paper summarizes and compares the integrity, anti noise, efficiency and complexity of line feature extraction through experiments. The results show that the improved line feature extraction algorithm can effectively weaken or remove the influence of sawtooth effect in the process of line extraction, so as to quickly obtain line features that meet the requirements of line matching. Therefore, as the basis of stereo matching advanced processing, line feature has great potential in image processing and pattern recognition.