Abstract: In the manufacturing industry, the welding quality has an important impact on the safety, reliability and service life of the products. Therefore, the detection and evaluation of weld quality is the key to quality control. The weld feature detection method based on line structure light is a non-contact and high precision detection technique,which is widely used in weld type identification and feature extraction. The paper first introduces the working principle and market distribution of line structure light technology, emphasizing the key role of this technology in the welding field. The paper further summarizes the current research achievements and challenges in this field, such as the adaptation to environmental light sensitivity and complex background, and the interference of detection by the high reflectivity and absorption rate of welding materials. Finally, future research directions are discussed, including the fusion of machine learning technology to enhance the performance and robustness of the algorithm, and the point cloud technology to improve the identification of small weld contour areas, demonstrating the importance and development potential of automatic welding technology in the manufacturing industry.