Abstract: Common appearance defects on enameled copper wire seriously compromise the safety and reliability of electrical products. To investigate fundamental formation mechanisms of these defects and guide process optimization, micro-morphologies and elemental compositions of solid particles, continuous particles, and paint film scratches on 0.5~2.0 mm enameled copper wires were characterized using laser scanning confocal microscopy (LSCM) and field emission scanning electron microscopy (FESEM), and formation causes were traced by correlating analytical results with actual production conditions. It was found that solid particles originated from the adhesion of contaminants, such as tar from oven outlet, onto the bare copper wire; continuous particles were caused by the vibration of coating die, which was induced by an insufficient paint liquid level, leading to local paint accumulation; and paint film scratches were primarily attributed to the rolling and crushing of hard foreign objects attached to guide wheels. The study demonstrated that microscopic analysis was an effective method for linking defect morphology to production parameters, and formation mechanisms of the three defect types were elucidated, providing a direct theoretical basis and technical support for developing targeted process improvements and enhancing product quality.