Abstract: In order to effectively improve the upgrading efficiency of biomass pyrolysis vapors,polyethylene pyrolysis volatiles were used as indirect hydrogenation material,and indirect hydrogenation upgrading of biomass pyrolysis vapors was conducted over HZSM-5 and its Ru,Ti and Sn modified versions to prepare bio-fuels.Besides,non-thermal plasma（NTP） technology was introduced to enhance the conversion process.The effects of metal modifications on the active radicals,organic phase yields,properties and compositions,and catalyst coking rates were explored.The results showed that under the action of NTP,the Ru and Ti modified species enhanced the formation of active radicals and activated more volatiles into the same radical scale,contributing to the integration of mixed vapors.Particularly,the yield and high heating value of organic phase by using TiHZ5 reached 58.73% and 38.73 MJ/kg,respectively.The modification of Ru,Ti and Sn significantly increased the relative contents of aromatic hydrocarbons in the organic phase,which were increased by 109.15%,208.55% and 52.52%,respectively,resulting in a decrease in the effective hydrogen to carbon ratio distribution of the product.In addition,the coking rates of Ru,Ti and Sn modified HZSM-5 were decreased from 12.88% to9.44%,4.95% and 10.91%,respectively.And Ti modification significantly improved the stability of catalyst.In general,under the action of NTP,Ti modified HZSM-5 had higher conversion efficiency and higher catalytic stability.