Objective To explore the clinical application value of Orem's self-care theory in patients with thyroid can-cer complicated with type 2 diabetes mellitus.Methods From September 2020 to December 2023,a total of 80 pa-tients with thyroid cancer complicated with type 2 diabetes mellitus admitted to Guangdong Second Traditional Chi-nese Medicine Hospital were selected as the research objects.According to the different nursing methods,they were divided into two groups,40 cases in each group.The control group was given routine nursing intervention,and the ob-servation group was given Orem's self-care theory intervention.The health behavior scores,disease self-efficacy scores,and negative psychological scores were compared between the two groups.Results After intervention,the health behavior scores in the observation group were higher than those in the control group,and the differences were statistically significant(all P<0.05).After the intervention,the disease self-efficacy score of the observation group was higher than that of the control group,and the difference was statistically significant(P<0.05).After intervention,the scores of Hamilton Anxiety Rating Scale and Hamilton Depression Rating Scale in the observation group were lower than those in the control group,and the differences were statistically significant(both P<0.05).Conclusion The imple-mentation of Orem's self-care theory management for patients with thyroid cancer complicated with diabetes mellitus can effectively promote the establishment of healthy behaviors for diabetes blood glucose control,improve patients'self-efficacy for the disease,and reduce patients'negative psychology.