Objective To analyze the characteristics of spirometry and type 2 inflammation indicators of patients with CVA， ACO and CA to determine their clinical utility in identifying and distinguishing among CVA， ACO and CA patients. Methods Clinical data from 483 patients diagnosed with bronchial asthma， CVA， and bronchial asthma combined with chronic obstructive pulmonary disease in the outpatient department of the First Affiliated Hospital of Soochow University from July 2023 to June 2024 were collected and divided into CA， CVA and ACO groups according to diagnosis. Comparison of spirometry， fractional exhaled nitric oxide （FeNO）， blood eosinophil （EOS）， serum total immunoglobulin E （tIgE） and other tests between CA and CVA， CA and ACO groups. Perform logistic regression analysis on significant test results， then construct receiver operating characteristic （ROC） curves to compare the area under the curve and corresponding cut-off values. Result There was a statistically significant difference in tIgE between the CVA and CA groups （P = 0.018）， whereas no significant differences were observed in FeNO and EOS. Additionally， no notable differences were found between the ACO and CA groups in tIgE， FeNO， or EOS. Finally， FEV1%pred （OR = 1.086， P = 0.019）， FEV1/FVC （OR = 1.153， P = 0.023）， and MEF50%pred （OR = 0.922， P = 0.045） were used to construct the discriminative model between CA and CVA. ROC curves were plotted， with FEV1%pred showing an AUC of 0.680 （P < 0.001）， a Youden index of 0.358， and a corresponding cutoff value of 89.200. FEV1/FVC had an AUC of 0.684 （P < 0.001）， a Youden index of 0.334， and a cutoff value of 76.075. MEF50%pred had an AUC of 0.668 （P < 0.001）， a Youden index of 0.309， and a cutoff value of 59.800. The combined sensitivity of these three measures was 0.909， specificity was 0.514， positive predictive value was 0.600， negative predictive value was 0.873， and the AUC was 0.773 （P < 0.001）， with a Youden index of 0.423. FEV1 （OR = 0.002， P = 0.045）， FEV1%pred （OR = 1.490， P = 0.006）， and FEV1/FVC （OR = 0.749， P = 0.005） were used to construct the discriminative model between CA and ACO. ROC curves were plotted， with FEV1 showing an AUC of 0.819 （P < 0.001）， a Youden index of 0.532， and a corresponding cutoff value of 2.060. FEV1%pred had an AUC of 0.788 （P < 0.001）， a Youden index of 0.501， and a cutoff value of 75.000. FEV1/FVC had an AUC of 0.891 （P < 0.001）， a Youden index of 0.678， and a cutoff value of 68.620. The combined sensitivity of these three measures was 1.000， specificity was 0.904， positive predictive value was 0.771， negative predictive value was 1.000， and the AUC was 0.973 （P < 0.001）， with a Youden index of 0.904. Conclusions Differences exist in the spirometry among CVA， ACO and CA. The spirometry results incorporated into the discriminative models provide good discriminative value for distinguishing between CA and CVA patients with similar clinical symptoms， as well as for identifying ACO in the CA population.