Objective To study the application of health education under the protection motivation theory on self-care agency and complications of patients with type 2 diabetes. Methods From Mar. 2015 to Mar. 2016, a total of 60 patients with type 2 diabetes in our hospital were taken as the clinical research objects, and they were divided into control group and observation group according to their education types. Both groups were given routine healthy education, besides, the observation group accepted additional healthy education under the protection motivation theory. Three months after intervention, the self-care agency and complications in the two groups were observed and compared. Results Three months after intervention, the scores of daily life management, medical management of diseases, emotion management and self-management behavior, and self-efficacy management score in the observation group were all higher than those in the control group, and their differences were statistically significant (P<0.05), the complications (fundus lesions, diabetic nephropathy, neurologic disorder, cerebral infarction, etc.) and total complication rate in the observation group were all lower than those in the control group, and their differences were statistically significant (P <0.01). Conclusion Health education under the protection motivation theory can not only significantly improve the self-care agency of patients with type 2 diabetes, but also reduce the of complication incidence of type 2 diabetes.