Objective To analyze the effect of Meleis transition theory in the intervention of family caregivers of advanced lung cancer patients.Methods From January 2022 to June 2023,94 patients with advanced lung cancer and their family caregivers treated in 4 hospitals of a tertiary A hospital in Zhejiang Province were selected by convenience sampling method,and they were divided into a control group(n=47)and an experimental group(n=47)according to random number table method.The family caregivers of the experimental group received a four-week intervention based on the Meleis transition theory on the basis of routine nursing education,including role recognition,disease knowledge,life care,psychological support,and social resource connection.Family caregivers in the control group received routine nursing education,caregiving education and guidance.The differences in the readiness,caring ability,psychological burden and patients'quality of life were compared between the 2 groups.Results There was no lost follow-up cases in the control group and experimental group.After intervention,the preparation,ability,and quality of life of family caregivers in the experimental group were better than those in the control group,and the psychological burden of caregivers was significantly lower than that in the control group(P＜0.05).Conclusion The intervention of caregiving ability of family caregivers based on Meleis transition theory can effectively improve the caregiving ability of caregivers,reduce the psychological burden of caregivers,improve the quality of care,and improve the quality of life of patients.