China has made remarkable achievements in the management of severe mental disorders, but there are few research reports on the risk of diabetes in severe mental disorders. Foreign studies have shown that the risk of diabetes increases the most in patients with severe mental disorders. Blood glucose control and strengthening the attention to diabetes in this population has become a new direction of work and research. The study found that the detection rate of diabetes in hospitalized patients with severe mental disorders in the Second People's Hospital of Jiangning District, Nanjing was 20.1%. Variables such as mental illness type and age were important factors for comorbid diabetes. It is called for diabetes screening in hospitalized patients with mental illness as soon as possible, to explore possible influencing factors, and to carry out evidence-based research in a timely manner. Patients' emotions should be paid attention to, and their exercise level should be mobilized to control their blood glucose level, so as to reduce the incidence and mortality of diabetes and other comorbidities.