Abstract: To investigate the effects of different parameters temperature（220 ℃-300 ℃）,reaction time（40 min-80 min）,total solid content（10%-30%）on the yields and qualities of bio-oil,Response surface method is used for analysis of hydrothermal liquefaction treatment process for pig carcass to obtain indicators of bio-oil quality such as higher heating value,C recovery rate and N residual rate.The results showed that all the reaction conditions have effect on hydrothermal reaction process,most of which is temperature. The biooil with the most satisfied single index was obtained from different reaction conditions. To be more specific,the highest yield of bio-oil obtained is 76.94%（278 ℃,64 min,29%）;the highest HHV obtained is 38.63 MJ/kg（290 ℃,47 min,30%）;the highest C recovery rate obtained is 93.16%（260 ℃,60 min,10%）,and the lowest N residual rate obtained is 15.52%（220 ℃,40 min,12%）.The elemental analysis of bio-oil shows that hydrothermal liquefaction can effectively reduce the content of N and O in bio-oil and improve the quality of bio-oil,meanwhile,the FT-IR and TG/DTG analysis shows that the chemical composition of bio-oil is complex and mainly composed of organic compounds with large molecular weight and long carbon chain.