Abstract: Gasification of fir sawdust using CO₂ as gasifying agent to produce syngas（H₂+CO）was performed in molten carbonate salts Li₂CO₃-Na₂CO₃-K₂CO₃（LNK）which was adopted as gasification medium and catalyst,and the effects of operating parameters such as CO₂ flow,CO₂ access method,kinds of metal oxides added and the additive Cr₂O₃ content in composite molten salts system on the distribution and yield of gas composition were investigated. The results show that CO₂ flow significantly affects the equilibrium of gasification reactions. The gasification effect of bubbling method is superior to that of sweeping method. The better gasification effect is achieved when the CO₂ flow is 99.8 L/h with bubbling method,and the content and yield of syngas reach 61.4% and 350.2 mL/g biomass,respectively. Among the added metal oxides,the promotion effect of Cr₂O₃ on biomass gasification is superior to that of MgO and Fe₂O₃. With the increase of Cr₂O₃ content,the syngas content first increases and then slightly decreases,and the maximum of syngas content is obtained at the Cr₂O₃ content of 10.0%,which is 67.9%.