Abstract: Cellulose is one of the most abundant renewable organic carbon resources in the world. Levoglucosenone (LGO) is a high value-added platform chemical derived from cellulose pyrolysis. In this study, the influence of ionic liquid catalyst on the production of LGO by catalytic pyrolysis of cellulose was revealed. The results showed that 1-butyl-2,3-dimethylimidazolium triflate performed best for the LGO formation. The reason was that the decrease in the length of the side chain weakened the interaction between the cation and anion of the ionic liquid, which increased the diffusion of the ionic liquid. LGO reached a yield of 15.6%-C at pyrolysis temperature of 300 ℃, and the recovery rate of ionic liquid attained to 95.9%. Besides, LGO yield only slightly decreased after 3 times re-utilization of the ionic liquid. The formation path of LGO was calculated by density functional theory. The result showed the lowest activation energy was 176.2 kJ/mol. Moreover, this method was effective to obtain porous char at the same time, and the highest specific surface area and pore volume were 389.4 m²/g and 0.689 cm³/g, respectively.