Abstract: In recent years,CRRC Zhuzhou Electric Locomotive Co. uses a standard metro car body platform for most  metro train applications. The standard metro roof uses a continuous extruded curved aluminum alloy profile structure, which is more suitable for application of friction stir welding technology. Friction stir welding is an energy-saving, material-saving, environmentally friendly, and green welding technology. In order to promote the application of friction stir welding technology in standard metro roof ,process research and verification will be carried out based on the previous stir welding technology for side walls and long floors. By conducting research on the design of the profile, the design of the fixture, the process design, the verification of welding parameters, and the fabrication of engineering prototype samples, the mechanical properties, internal defects, and profile accuracy of the standard metro roof friction stir welding process were ensured to meet relevant design and quality requirements.