Abstract: This paper introduces the hazards of scaling, the causes of formation and the treatment measures.This reaction are controlled by three factors, which are the content of calcium ion, the content of hydrocarbonate and pH value.The SI saturation index method has been applied in predicting the formation of scaling during in-situ leaching field test.It is shown that the main component of the scaling is calcium carbonate through chemical analysis.Adding a certain concentration of CO₂ to the lixiviant can depress the pH value and dissolve calcium carbonate scaling.As a result, the volume of injection wells are recovered and good effects are gained.