Abstract: In order to effectively recover the tin metal in the waste copper-based tin plating circuit board, the H₂SO₄-CuSO₄-Cl^- system was used for treatment in the experiment. The effects of copper ion concentration, initial sulfuric acid concentration, temperature, time and other factors on the tin removal rate were investigated in detail, and the cycle test was carried out. The experimental results show that the optimal tin removal effect is achieved under the conditions of 0.4 g/L copper ion concentration, 57 mL/g liquid-solid ratio, 50 g/L sulfuric acid concentration, 3.65 g/L chlorine ion concentration, 600 r/min stirring speed, 70℃ reaction temperature and 12 min reaction time. The tin removal rate of the coating reached 98.54%, and tin was transformed into Sn²⁺ and Sn⁴⁺ in the solution. After deplating, H₂O₂ was added to the solution to further oxidize it into Sn⁴⁺. Most of the Sn⁴⁺ in the solution was separated in the form of β-tinic acid precipitation, and the tin content of the dried β-tinic acid product was 69.34%-69.89% higher. The tin removal rate after five cycles is about 98.5%, the test results show that Cu²⁺ basically has no loss, and the deplating solution can form a cycle. The system solves the problem that metal copper covers on the surface during the replacement process, which affects the effect of tin removal, improves the efficiency of tin removal, and can effectively strip the tin coating and substrate. Cu²⁺ is changed into Cu⁺ after displacement and tin removal. By adding hydrogen peroxide, Cu⁺ in the deplating solution is oxidized to Cu²⁺, so this method can recycle the tin removal solution.