Abstract: In view of the characteristics of acid leaching of uranium mine, the factors affecting the acidity control of the leaching agent and the main source of acid consumption are discussed from the different leaching stages of the mining area, the requirements for the leaching of uranium ore, the composition of the surrounding rock and the blockage of the ore layer.And the control method of the acidity of the leaching agent is discussed.It concludes that the main source of acid consumption in acid leaching is calcite, iron oxide, sulfide, chlorite and other non-uranium minerals.The low acid leaching should be considered first, and it is appropriate to reduce the concentration of the leaching agent in different leaching stages to meet the concentration of the remaining sulfuric acid in the leaching solution of 0.5 to 2.In the practical application of the deposit No.511, the acidity of the leaching agent is about 5 g/L during the leaching period, and the final stage of dissolution is 2-3 g/L, which can meet the production needs.