Abstract: To address manufacturing precision bottlenecks in core conductive components for large-capacity electric arc furnaces in modern metallurgical industries, this study investigates material removal mechanisms and error evolution patterns of large-sized purple copper forgings under complex machining conditions. Based on the 2024 upgrade project for a 45 MW ultra-high-power electric furnace at a domestic metallurgical group, the research conducts in-depth analysis of extreme plastic deformation, thermal conduction hysteresis effects, and stress release deformation characteristics during T2 pure copper machining. Experimental data from cutting tests and engineering measurements reveal how dynamic chip accumulation, non-uniform thermal stress distribution, and deep-hole chip evacuation challenges collectively impact final machining accuracy. Grounded in micro-cutting mechanics, fluid dynamics, and metal physics theories, optimized solutions include: variable helix angle tool configuration redesign, hybrid thermal control with micro-lubrication and high-pressure internal cooling, adaptive flexible clamping systems, and variable-parameter low-frequency vibration deep-hole drilling techniques. Quantitative comparison results verify that the new process system strictly controls the geometric tolerance of meter-scale large copper parts within 0.02 mm and stabilizes the surface roughness at Ra 0.8 μm, completely eliminating surface tearing and deep-hole scratching defects. Successful implementation significantly extends operational lifespan and enhances electrical energy conversion efficiency of electric furnace conductive systems, establishing comprehensive theoretical foundations and practical paradigms for precision manufacturing of heavy-load, high-current conductive core equipment.