Objective To investigate and analyze the incidence and clinical characteristics of malnutrition in patients with tuberculosis and type 2 diabetes. Methods four hundred patients with tuberculosis and type 2 diabetes were diagnosed in the tuberculosis Department of West China Hospital of Sichuan University from June 1, 2018 to April 30, 2023. The incidence and clinical characteristics of malnutrition were analyzed using the nutritional risk Screening 2002 score and the Global Malnutrition Leadership Initiative criteria. Results 170 patients (42.5%) were malnourished. In malnourished patients, 78 cases (45.9%) had fever, 132 cases (77.6%) had cough, 44 cases (25.9%) had hemoptysis, and 36 cases (21.2%) had night sweating. Compared with the non-malnourished patients, the difference was statistically significant (P<0.05). Lymphocyte count was (1.0±0.5)×109/L, albumin was (31.4±20.5)g/L; CD3 count 792.7±205.0, CD4 count 535.4±15.0, CD8 count 429.5±123.0, CD3%: 65.5%±11.1%, CD4%: 39.1%±9.6%, CD8%: 19.1%±9.6%, CD4/CD8: 1.3±0.2, which were significantly lower than those in the group without malnutrition. Pulmonary cavity occurred in 44 cases (25.9%), lesions in 2 - 4 lung fields in 76 cases (44.7%) and lesions in ≥5 lung fields in 52 cases (30.6%), all of which were significantly higher than those in the non-malnutrition group. The above differences were statistically significant.Conclusion We should pay more attention to the screening of malnutrition in patients with tuberculosis and type 2 diabetes. Patients with malnutrition have more obvious clinical symptoms, lower immunity, and more serious imaging lesions.