Abstract: An kinetic model of biomass and polypropylene co-gasification was built,and the model was verified by experimental data,use six kinds of biomass and polypropylene as co-gasification reactants,steam as gasification agent.The effects of temperature between 300-1000℃，pressure between 0.1-0.8 MPa,mass ratio of polypropylene and pine sawdust between 0.5-2.5,and different biomass types on the co-gasification characteristics of biomass and polypropylene were calculated.After the addition of polypropylene in the gasification of pine sawdust,the maximum gas yield and maximum gas yield rate increased,the maximum total gas flow rate increased by 21.46%,the maximum gas yield rate increased by 4.64%,and the maximum H₂ and CO yields increased by 54.27% and 79.51%,respectively.The increase of pressure is not conducive to the increase of H₂ and CO content in co-gasification gas,but is beneficial to the increase of CH₄ content.The order of H₂ content from co-gasification of six types biomass and polypropylene is,peel＞cotton stalk≈corn straw＞poplar sawdust＞rice straw＞Enteromorpha prolifera.It is beneficial to increase the yield of H₂,CO and CH₄ on increasing the blending ratio of polypropylene.