Abstract: Visual sensing technology is a commonly used perception method in metal processing at present and is widely applied in scenarios such as welding and metal cutting. This article mainly elaborates on the application of visual sensing in the welding processing technology, introduces the related technical principles, describes and summarizes the parts of the entire process that use visual sensing, and discusses the advantages and disadvantages of various methods and their applicable scenarios. Finally, it discusses the current technical challenges and future development of visual sensing technology. In complex and changeable intelligent application scenarios, the singularity of visual sensing technology is no longer sufficient to meet actual demands. The deep integration of visual sensing technology with artificial intelligence will be the main theme of the industry in the future. The collaborative and deep integration of multi-visual sensing aims to build an intelligent visual sensing system that can autonomously perceive the environment, analyze data in real time, and make independent decisions, thereby significantly enhancing the system's intelligence level and expanding its application potential and efficiency in multiple fields.