Abstract: Xinjiang has abundant reserves of high-alkali coal, but due to the high content of alkali metal elements such as Na and K, it has caused problems of slagging and contamination during the combustion of high-alkali coal. Fluidized preheating can increase fuel activity and promote alkali metal precipitation, and preheating combustion is expected to achieve clean and efficient combustion of high-alkali coal. At present, the kinetic characteristics of fuel reactions after preheating high-alkali coal have not been elucidated. Therefore, in order to investigate the dynamic effects of preheating air equivalence ratio （λ） on the preheating of high-alkali coal and coke, a high-alkali coal circulating fluidized bed preheating experiment was conducted. Through thermogravimetric （TG） experiments, the changes in activation energy and pre exponential factor were analyzed, and the dynamic characteristics of raw coal and preheated coke were studied. The results showed that when the preheating air equivalence ratio increased from 0.28 to 0.40, the maximum weight loss rate of preheated coal coke decreased, and the ignition and burnout points increased. Before the mass conversion rate reaches 0.5, the reaction activation energy and pre exponential factor of preheated coal coke are higher than those of raw coal, while the conversion rate is within the 0.5~0.8 stage, and the results are opposite. This is because the volatile matter content and coke reaction characteristics of raw coal and preheated coal coke are different in different reaction stages. The reaction rate constants of raw coal and preheated coal coke were calculated at different combustion temperatures, and it was found that the reaction rate constants of preheated coal coke were higher than those of raw coal, and the reaction rate constants increased first and then decreased with the increase of the preheating air equivalence ratio. When the preheating equivalence ratio is 0.31 and the combustion temperature is 950 ℃, the calculated reaction rate constant of preheated coal coke is about 13 times that of raw coal. The research results are expected to provide theoretical and data support for the development and application of high alkali coal preheating combustion technology.