To investigate the fracture of ER70S-6 wire rod during drawing， the microstructure of the fractured wire rod was examined by optical microscopy and scanning electron microscopy. A hard abnormal constituent was identified as bainite based on its hardness and morphology. Bainite impedes coordinated deformation of the microstructure and is the primary cause of wire-rod fracture during drawing. The tensile strength of the fractured wire rod was 1.07 times that of the normal wire rod， while its reduction of area was 95% of that of the normal wire rod； these differences in mechanical properties further increased its susceptibility to drawing fracture. To improve wire rod quality， the carbon mass fraction was controlled at approximately 0.070%. After rolling， the laying temperature was reduced from 880 °C to 850 °C， the roller conveyor speed was reduced from 0.15 m/s to 0.13 m/s， and the average cooling rate in the transformation region was reduced from 1.2 °C/s to 0.8 °C/s. The optimized wire rod consisted mainly of ferrite and pearlite， with no obvious bainite morphology observed. These composition and cooling-process parameters promote ferrite and pearlite transformation， suppress bainite formation， and thereby improve the drawability of the wire rod.