As a basic lithium salt, lithium carbonate is not only widely used in the traditional chemical industry, but also an important raw material for the production of lithium batteries.In recent years, the booming development of lithium battery industry has greatly promoted the research on extraction and preparation of raw material of lithium carbonate.In order to extract lithium from spodumene to prepare lithium carbonate, the precipitation dissolution equilibrium theory was used to analyze the impurity removal law of lithium leaching solution.In this study, spodumene from a domestic place was used as raw material to explore the process rules of preparing lithium carbonate.The surface of spodumene was smooth and dense, so it was difficult to react with most acid and alkali（soluble in hydrofluoric acid）.Therefore, through the early exploration of reaction temperature and reaction time, α-spodumene could be completely transformed into β-spodumene under 1 050 ℃ with calcination time of 30 minutes.After calcination transformation, the raw material of β-spodumene could be mixed with sulfuric acid to calcine to convert lithium into soluble lithium.As a result, about 98% of lithium in spodumene could enter the liquid phase and get the final lithium leaching solution.In order to prepare high-purity lithium carbonate, the process of purification and impurity removal was explored to obtain more accurate pH range of each ion precipitation.The pH range of Al ³⁺, Fe ²⁺, Fe ³⁺, Mg ²⁺, Ca ²⁺ precipitation was discussed by using the principle of dissolution equilibrium through HSC thermodynamics software and consulting relevant data.Then the three-step decontamination purification condition was determined according to the dissolution equilibrium theory：1）neutralizing the pH to 6.5 to remove Al ³⁺ and Fe ³⁺;2）adding oxidant to oxidize Fe ²⁺ to Fe ³⁺ and adjusting the pH to 8.0 to remove Fe ³⁺;3）adjusting the pH to 10.0 by adding the theoretical amount of carbonic acid sodium（calculated by Ca ²⁺ in the liquid phase）, final concentration of Al ³⁺, Fe ³⁺, Mg ²⁺, etc.was lower than 10 ^-6 mol/L, and mass content of Ca ²⁺ was about 2×10 ^-5.