Abstract: The visual sensing technology based on laser structured light is currently the mainstream of sensing technology that realizes the automation and intelligentization of welding process. Different types of visual sensors based on laser structured light and their typical applications in welding field were firstly and briefly introduced. Then,in view of the three stages of image preprocessing,laser centerline extraction,feature point recognition in image processing,the traditional image processing algorithms at each stage were introduced in detail,respectively. After that,for some typical scenarios in welding applications,examples are given to illustrate the more characteristic image processing algorithms and the image processing effects obtained by their applications,including detection accuracy and real-time. Finally,the further research and application of visual sensor based on laser structured light and its future development direction in welding field were proposed.