Abstract: The extraction of lithium from amblygonite by the sulfuric acid method was studied. The results showed that when the mass ratio of ore to sulfuric acid was 1:0.4, the roasting temperature was 780~820℃, and the mass ratio of leaching liquid to solid was 1.6:1, the extraction rate of lithium could reach above 96%. The Al³⁺, Fe³⁺ and PO₄^3- impurities in the lithium sulfate solution could be completely removed by adjusting the pH value of NaOH to 12. The obtained lithium sulfate solution could be complexed with Ca²⁺ by EDTA and reacted with Na₂CO₃ solution to obtain a battery grade lithium carbonate. The optimization process is mainly aimed at the two technological difficulties of dilute paste and fluorine disposal in the mixed acid material. Adding water absorbent materials into the mixed acid material can improve the thin paste state of the material, which is conducive to subsequent industrial production operations. After calcining amblygonite and then roasting it with mixed acid, the paste of mixed acid can be eliminated, and the extraction rate of lithium can reach more than 97%. During acidification, the thermal insulation reaction at approximately 280℃ can displace fluorine and reduce the fluorine ion content in lithium sulfate solution, fluorine can be recovered, and the tail slag AlPO₄ has a higher recovery value.