Abstract： Objective:To explore the role of carlizumab combined with pemetrexed and cisplatin in advanced liver cancer with first-line chemotherapy failure.Methods:A total of 118 patients with advanced primary liver cancer who failed first-line chemotherapy in our hospital from January 2019 to May 2021 were selected and randomly divided into control group and observation group,with 59 cases in each group.The control group was treated with pemetrexed and cisplatin,and the observation group was treated with carrelizumab.The anti-cancer effect,programmed death receptor-1(PD-1)expression,serum alpha-fetoprotein(AFP),vascular endothelial growth factor(VEGF)levels,incidence of adverse reactions and survival rate were compared between the two groups.Results:The clinical benefit rate and total effective rate of the observation group were higher than those of the control group(P<0.05).After treatment,the levels of PD-1,serum AFP,VEGF in the observation group were lower than those in the control group(P<0.05).There were no significant differences in adverse reactions between the two groups(P>0.05).The survival rate of the observation group was higher than that of the control group within 1 year(P<0.05).Conclusion:Carelizumab can improve the therapeutic effect of advanced liver cancer who failed to receive first-line chemotherapy,reduce the expression of PD-1 and the levels of tumor markers,which is safe and can improve the survival rate.