Abstract: In response to the complex manufacturing process, significant quality fluctuations and extended manufacturing cycles associated with slender ratio thin-walled cylinder components, a dual-robot collaborative machining system and method for thin-walled cylinder parts with slender ratio have been proposed. This approach establishes a novel production mode for slender ratio thin-walled cylinder components, overcomes the manufacturing process bottlenecks of such components, and creates an independent and controllable machining system. A three-dimensional laser scanning device acquires the point cloud data of the cylinder parts, and a global coordinate system is established to calibrate the relationship between the cylinder parts and the robots. This method replaces the traditional CNC machining processes of scribing and alignment, and the material allowance of the cylinder parts is determined based on the automated scanning and measurement results. The milling process parameters are optimized considering the flutter mechanism inherent in dual-robot collaborative machining, and the robot machining trajectories are planned in accordance with the structural characteristics of the robots. The effectiveness and superiority of proposed method are verified through a dual-robot collaborative machining experiment on a cylinder test piece. Results indicate that the dual-robot collaborative machining method enhances the production efficiency of cylinder parts by more than 40%.