Abstract: A coupled heat transfer and reaction kinetics model was established to study the lithium production efficiency and reduction rate of lithium production retorts. Numerical simulation of the pellet reduction process by this model was performed to obtain the time distributions of pellet temperature and reduction rate, and the effect of effective heat transfer coefficient outside the retorts on the pellet reduction process was analyzed. It is found that the low thermal conductivity of pellets and the chemical reaction equivalent heat sink are the main factors affecting the pellet reduction process. In the beginning of the reaction, heat transfer is the main controlling factor, but in the later, reaction kinetics is the controlling factor. The effective heat transfer coefficient outside the retorts has less influence on the pellet reduction process. Enhancing the heat transfer coefficient inside the retorts is an effective way to improve the production efficiency.