Objective:To explore the effects of contingency theory-based health education in patients with diabetes mellitus.Methods:Totally 112 diabetic patients admitted into Affiliated Hospital of Shaoxing University from January 2017 to December 2018 were selected by convenient sampling and randomized divided into the control group and the intervention group, with 56 patients in each group. Patients in the control group received routine care, while patients in the observation group received contingency theory-based health education. The health knowledge level, self-care ability, self-efficacy and quality of life of the two groups before and after intervention were compared.Results:The health knowledge level of the intervention group after intervention was higher than that of the control group [ (17.15±2.28) vs. (13.20±2.94) ], and the difference was statistically significant ( P<0.01) . The scores of self-care ability, self-efficacy and quality of life of the intervention group were higher than those of the control group, and the differences were statistically significant ( P<0.01) . Conclusions:The contingency theory-based health education can improve the disease knowledge, self-care ability, self-efficacy and quality of life of diabetic patients, which is worth promoting in clinical practice.