Abstract: The effect of sulfuric acid solution of different concentration on the electrochemical cold drawing（ECD） of Q235 steel bar after electrochemical corrosion was studied. The results show that the electrochemical corrosion rate of Q235steel bar in 0.95 mol/L sulfuric acid solution is the largest, the surface corrosion degree is the largest, the surface hardness is the lowest, and the softening degree of the surface layer of the bar is the largest. When ECD is carried out in 0.95 mol/L sulfuric acid solution, the dislocation density is the lowest in the deformed layer of the bar surface, the surface deformation layer is the thinnest, and the deformation degree of the grains in the surface deformation layer is the smallest, so that the work hardening degree of surface layer of the bar is the smallest, and the reduction rate of the drawing force is the largest, which makes drawing easier.