Objective: To explore the prevalence and related factors of osteoarthritis in patients with type 2 diabetes mellitus, and provided a scientific basis for the prevention of the comorbidity. Methods: The data were obtained from the database of all designated medical institutions in Beijing from 2015 to 2017. Data of the adult patients with type 2 diabetes mellitus were collected for descriptive analysis, and a Logistic regression model was used to explore the related factors of osteoarthritis in the patients with type 2 diabetes mellitus. Results: A total of 1 046 264 diagnosed type 2 diabetes mellitus adult patients were included in our study, with an average age of 63.07 years, and 50.78% were males. Among the patients with type 2 diabetes mellitus, there were 341 561 cases with osteoarthritis, and the prevalence of osteoarthritis was 32.65%. The prevalence of females (38.05%) was higher than that of males (27.41%), and the difference was statistically significant (P<0.05). Osteoarthritis occurred in all age groups among the patients with type 2 diabetes mellitus, with the highest prevalence of osteoarthritis in the age group of 65-69 years (36.76%), and the lowest prevalence in the age group ≤44 years (14.3%). Before the age of 70, the prevalence increased with age. Further analysis of related factors for osteoarthritis in the patients with type 2 diabetes mellitus showed that female (OR=1.62, 95%CI: 1.61-1.63), age (OR=1.01, 95%CI: 1.01-1.01), had other comorbidities (OR=1.19, 95%CI: 1.18-1.21), used hypoglycemic drugs (OR=0.79, 95%CI: 0.78-0.80), having the cardiovascular disease (OR=1.13, 95%CI: 1.11-1.15), having cerebrovascular disease (OR=1.25, 95%CI: 1.23-1.28), and having nephropathy (OR=1.61, 95%CI: 1.51-1.71) were associated with the osteoarthritis in the type 2 diabetic mellitus patients. Conclusion: Our study revealed that the prevalence of osteoarthritis in patients with type 2 diabetes mellitus is high in Beijing area. Health education and disease monitoring should be strengthened in middle-aged and elderly patients. Screening for comorbidities should be carried out as soon as possible, with the focus on menopausal women.