In order to effectively investigate the variation of gas production characteristics of biomass under normal-speed pyrolysis conditions,the gas production rate,gas production component yield and gas production calorific value of pine sawdust with adding Na2CO3,CaO and Fe2O3 were systematically analyzed.In the experiment,an improved tube furnace was used to research the pyrolysis process with the temperature from 350℃ to 750℃.The results indicate that the gas yield rises with the increase of temperature without additives,reaching 19.59％ at 750℃.The liquid yield reaches 59.38％ at 450℃ and then the yield change is small.CaO increases the calorific value of the pyrolysis product gas due to the adsorption of CO2.Na2CO3 is fused with inorganic substances in the biomass to form a char skeleton structure.The effect of Fe2O3 on H2 is more obvious at higher temperature.Na2CO3 has the most obvious effect on the pyrolysis of pine sawdust among the discussed additives,which effectively promotes the production of H2.