Objective To analyze the nutritional status and risk factors of disease condition grading in patients with chronic obstructive pulmonary disease (COPD), and to provide the reference for clinical diagnosis and treatment.. Methods A total of 518 patients with COPD who were admitted to the hospital from February 2020 to February 2023 were selected as the study subjects (COPD group). Among the 520 cases of non-COPD patients in respiratory and critical care wards were included in control group . The patients with COPD were divided into 265 cases in malnutrition group and 253 cases in normal nutrition group according to the nutritional status. The nutritional status of patients with different disease condition grades was observed . The basic information and clinical examination status were compared between both groups, and multivariate logistic regression analysis was used to explore the risk factors of malnutrition in patients with COPD. Results The nutritional indicators of BMI, IBM and ALB in COPD group were lower than those in control group (P<0.05). The higher the disease condition grade , the lower the levels of nutritional indicators (P<0.05). The proportions of smoking history, number of acute exacerbations ≥twice a year, comorbidity types≥4, ALB<35 g/L, CRP≥60 mg/L, CAT score≥10 points and FEV1/FVC<50% in malnutrition group were higher than those in normal nutrition group while the proportion of ventilator use was lower than that in normal nutrition group (P<0.05) . Multivariate Logistic regression analysis showed that the number of acute exacerbations≥ twice a year, comorbidity types≥4, CRP≥60 mg/L and FEV1/FVC<50% were independent risk factors of malnutrition in patients with COPD, and ventilator use was a protective factor (P<0.05). Conclusion The nutritional status of COPD patients is poor , and the more serious the disease condition grade , the worse the nutritional status . The number of acute exacerbations , types of concurrent diseases , CRP , FEV1/FVC are all influencing factors of malnutrition in COPD patients.