Abstract: As the core load-bearing structure of space launch vehicles, the manufacturing process of launch vehicle tanks, especially welding technology, directly impacts the structural integrity, lightweight level, and flight reliability of rockets. The current research status and development trends of rocket tank welding technologies globally are comprehensively reviewed, with a focus on the comparative analysis and interrelationships of different technical routes. Firstly, from the perspective of material evolution, the applications of aluminum alloy, stainless steel, titanium alloy, and composite materials in tank manufacturing and the challenges they pose to welding technology are compared. Secondly, an in-depth analysis is conducted on the improvements and limitations of traditional fusion welding technology, with a focus on the extensive engineering practice of friction stir welding (FSW) as a revolutionary technology in the manufacturing of launch vehicle tanks both domestically and internationally, revealing its advantages in performance and efficiency. Special attention is paid to intelligent and automated welding technologies, including frontier advancements such as robotic welding, digital twins, and quality prediction, and their roles in enhancing manufacturing levels are evaluated. Through a comparative analysis of research results from both domestic and international sources, the current technical needs and development directions of welding processes in terms of large-scale, lightweight, high reliability, intelligence, and reusability are revealed. Finally, the deficiencies of existing research are summarized, and the development trends of welding processes for launch vehicle tanks in the future are envisioned, emphasizing the key role of new materials, new structures, intelligence, and multi-technology integration in enhancing the manufacturing capabilityl of tanks.