A roughening solution electrolysis device, comprising a reaction cell and an electrolysis system. The reaction cell comprises a roughening solution. The electrolysis system comprises an isolating means, an electrolytic anode, and an electrolytic cathode provided in the reaction cell, and an energy supply means. The electrolytic anode and the electrolytic cathode are both electrically connected to the energy supply means; the isolating means contains an electrolyte; the electrolytic cathode is immersed in the electrolyte, the electrolytic anode is immersed in the roughening solution, and the isolating means is partially immersed in the roughening solution. By means of an electrolytic reaction, some of the Cr3+ ions in the roughening solution are subject to an anodic reaction with the electrolytic anode to generate hexavalent chromium, and the remaining Cr3+ ions enter the isolating means, thereby greatly reducing the concentration of Cr3+ ions in the reaction solution and ensuring the roughening capability of the roughening solution so as to achieve a long service life. In addition, intensive binding between an electroplated coating and an electroplated part is ensured, such that high electroplating quality is achieved for the electroplated part.