Taking the typical low-rank coal in northern Shaanxi as the research object in this work, the combustion performance and kinetic characteristics of semi-coke under different pyrolysis conditions were studied by thermogravimetric analysis, and the kinetic parameters were obtained using the Ozawa method. The average activation energy of all samples was obtained by the equal conversion method. The results showed that the lower the pyrolysis temperature and the shorter the holding time were, the better the combustion performance of semi-coke was; the larger the particle size was, the more obvious the difference in combustion performance was. The pyrolysis heating rate had little effect on the combustion performance of semi-coke. Pyrolysis temperature had a large effect on the combustion performance of semi-coke. 550℃ was the suitable pyrolysis temperature for preparing semi-coke with high combustion reactivity in this study. With the increase of the conversion rate, the activation energy of semi-coke prepared with two kinds of raw coal with different particle sizes decreased. When the pyrolysis temperature of 1~3 mm raw coal was 550℃, the semi-coke obtained during combustion conformed to the reaction order model. The chemical reaction was the limiting link, and the most probable mechanism function of the reaction was f(α)=(1–α)2.