Background. The etiology of sudden deafness is still unclear. In recent years, people’s life rhythm is getting faster and faster. Fatigue, environment, diet, psychology, and other factors have increased the morbidity rate of sudden deafness and improved the quality of life of patients. And work efficiency is greatly affected. Aims. A study to investigate the clinical efficacy of postauricular injection of methylprednisolone sodium succinate in the treatment of sudden deafness with type 2 diabetes. Materials and Methods. Sixty patients with sudden deafness who were treated in our hospital from January 2018 to October 2020 were selected as the subjects of this prospective study and divided into 30 cases each in the comparison group and the observation group according to the random number remainder grouping method. The comparison group was treated conventionally, and the observation group was treated with postauricular injection of methylprednisolone sodium succinate on the basis of the comparison group. Patients in the two groups were observed and compared on the 3rd, 6th, and 9th days after treatment with pure-tone hearing threshold checks and regular monitoring of blood glucose, blood rheology, and other indexes. Results. On the 7th, 14th, and 30th days after treatment, the pure-tone audiometric thresholds of the two groups were gradually decreased, and the changes in the pure-tone audiometric thresholds in the observation group were greater than those in the control group. After lunch on the 6th day and after lunch on the 9th day, it was lower than that in the control group, and the difference was statistically significant ( P < 0.05 ). 30 days after treatment, the blood viscosity, fibrin, and platelet aggregation rate of the observation group were significantly lower than those of the control group. After treatment, the clinical efficacy rate of the observation group was 96%, which was significantly higher than that of the control group, 80%, and the above differences were statistically significant ( P < 0.05 ). Conclusion. Treatment with postauricular injection of methylprednisolone sodium succinate has shown better therapeutic recovery in patients with sudden deafness, improved pure-tone hearing threshold, reduced risk of blood glucose elevation, and improved clinical outcomes for patients with sudden deafness, providing some reference for the treatment of patients with sudden deafness.