The work aims to propose technical scheme for stable cleaning of oxygen-free copper by solution formulation experiment, corrosion mechanism determination and cleaning solution concentration characterization. Solution formulation experiment for the formula consisting of chromic anhydride and concentrated sulfuric acid was performed and results were compared and analyzed by SEM and corrosion rate. Effects of copper concentration on the corrosion rate were studied by electrochemical cyclic voltammetry. Copper concentration and Cr VI concentration in the solution were analyzed by EDTA complexometric titration and oxidation-reduction titration respectively. Solution with chromic anhydride of 60~80 g/L+sulfuric acid of 40~60 mL/L+residual water was feasible for cleaning and could obtain a uniform and stable surface. Chromic anhydride acted as an oxidizing agent due to its strong oxidation while sulfuric acid adjusted acidity of the solution. Appropriate concentration of copper ion had obvious auxo-action on chemical reaction. Excessive mass concentration of copper ions (>5 g/L) had inhibitory effect on corrosion kinetics and corrosion rate. The appropriate concentration of stable cleaning solution for oxygen-free copper is proposed and the specific results of the corrosion mechanism and solution characteristics are obtained.