〔Abstract〕 To explore the value of combined indicators of prognostic nutritional index ( PNI) ，nutri- tional risk screening 2002 scale ( NRS2002 ) ，body mass index ( BMI) ，monocyte / lymphocyte ratio ( MLR) ， platelet / lymphocyte ratio ( PLR) ，and neutrophil / lymphocyte ratio ( NLR) in evaluating the severity of pulmonary tuberculosis ( PTB) ．Methods A total of 175 patients with pulmonary tuberculosis were selected as the study group，and 175 healthy subjects who underwent physical examination during the same period were selected as the control group．According to the range of lung lesions，the patients were divided into mild to moderate group ( ＜3 lung fields，n = 110) and severe group ( ≥3 lung fields，n = 65) ，PNI，NRS2002，BMI and peripheral blood MLR , PLR and NLR levels were compared between the two groups．Spearman rank correlation was used to analyze their correlation with the severity of the disease．A multivariate logistic regression model was established．A nomo- gram was drawn，and the efficiency of the model was evaluated by receiver operating characteristic ( ROC) curve， calibration curve，decision curve．Results The PNI，BMI，peripheral blood lymphocyte and albumin levels in the study group were lower than those in the control group ( P＜0. 05) ，while the MLR , PLR and NLR levels were sig- nificantly higher than those in the control group ( P＜0. 05) ．The NRS2002，MLR , PLR and NLR levels in the se- vere group were higher than those in the mild and moderate group ( P＜0. 05) ，while the PNI and BMI levels were lower than those in the mild and moderate group ( P＜0. 05) ．NRS2002 and peripheral blood MLR , PLR and NLR levels in patients with pulmonary tuberculosis were positively correlated with the severity of the disease ( r = 0. 250， 0. 509，0. 431 and 0. 488) ．PNI and BMI were negatively correlated with the severity of the disease ( r = －0. 516， - 0. 231) ．Multivariate Logistic regression showed that NRS2002 and NLR were independent risk factors for severe disease，while PNI was a protective factor．The areas under the curve ( AUC) of NRS2002，NLR , PNI，and com- bined detection for evaluating the severity of pulmonary tuberculosis were 0. 692，0. 777，0. 786，and 0. 860，re- spectively，the sensitivity of the combined prediction was 81. 54% and the specificity was 76. 36%．The combined detection had better evaluation efficiency for severe pulmonary tuberculosis than the single indicator ( P ＜0. 05) ． Conclusion NRS2002 and NLR are independent risk factors for severe disease，while PNI is a protective factor． The combined detection model has a good fit，which can improve the evaluation efficiency and has potential for clin- ical application．