Objective:To investigate the effect and prognosis of EGFR-TKI combined with PP(peme-trexed+cisplatin)chemotherapy in the treatment of epidermal growth factor receptor(EGFR)-mutated ad-vanced lung adenocarcinoma.Methods:This study was conducted from January 2019 to January 2021.A to-tal of 105 patients with EGFR-mutated advanced lung adenocarcinoma were selected,and divided into the combination group(54 cases)and the control group(51 cases)according to the treatment plan.The control group was treated with second-generation EGFR-TKI(dacomitinib).The combination group was treated with dacomitinib and PP chemotherapy,with 21 days as a cycle.Efficacy,tumor markers and progression-free survival were compared between the two groups.Results:The objective remission rate and disease control rate in the combination group(27.78%and 88.89%)were higher than those in the control group(9.8%and 68.63%)(P<0.05).The difference values of serum carbohydrate antigen 125(CA125),carcinoembryonic an-tigen(CEA),tissue polypeptide antigen(TPA)and cytoplasmic thymidine kinase(TK1)levels before and after treatment in the combination group were higher than those in the control group(P<0.05).The incidence rates of thrombocytopenia,diarrhea,enteritis,stomatitis,decreased appetite,liver dysfunction,renal dys-function and rash in the two groups were close(P>0.05).The 1-year and 2-year progression-free survival rates in the combination group(81.48%and 35.19%)were higher than those in the control group(62.75%and 17.65%)(P<0.05).The median progression-free survival time of the combination group and control group were 19.0 months and 15.1 months.There is a difference in the survival curves between the two groups(P<0.05).Conclusion:Second-generation EGFR-TKI combined with PP chemotherapy can significantly prolongs progression-free survival,without increasing adverse reactions.