Abstract: To address the issues of low machining accuracy, inefficient processing of complex parts, and significant variations in axial dimensions in domestic large-scale CNC vertical lathes, a ϕ1 600 mm moving-beam turning-milling compound CNC vertical lathes was developed. The structural design for turning-milling compound machining was optimized through modular and digital design technologies. Key technical research was conducted on high-precision spindle structures and multi-gear positioning accuracy retention for the crossbeam, leading to a reconfiguration of the machine's main structure. The lathe comprises 11 modules, including the base, column, crossbeam, ram, spindle, tool magazine, three sets of axis drive mechanisms, and two drive gearbox units. Finite element analysis was performed under identical constraints and cutting conditions to simulate extreme working conditions. Comparative static analysis between the new and old structures indicates that rigidity in both axial directions increases by over 15%, while deformation of main components decreases by 10%. Cutting tests confirm that the two-axis positioning accuracy reaches 0.012 mm, surpassing imported equipment and exceeding specified indicators. Application results demonstrate that the compound machine tool significantly improves processing efficiency, validating the structural design and providing theoretical and practical guidance for compound lathe development.