Objective To evaluate the diagnostic value of fiberbronchoscopy combined with rapid on-site evaluation (ROSE) in pulmonary infection. Methods Patients with pulmonary infection in a hospital from July 2017 to June 2018 (fiberbronchoscopy group: performed routine fiberbronchoscopy) and from July 2018 to June 2019 (fiberbronchoscopy+ROSE group: performed fiberbronchoscopy combined with ROSE examination) were selected, the examination results of two groups of patients were compared, confirmed diagnostic results of 6-month follow-up were compared with on-site evaluation results of two groups, Kappa value was calculated and receiver operating characteristic (ROC) curve were plotted to evaluate diagnostic efficacy. Results A total of 438 patients were enrolled, 207 were in fiberbronchoscopy group and 231 in fiberbronchoscopy+ROSE group. Compared with fiberbronchoscopy group, the time of the first examination was longer in fibrobronchoscope+ROSE group(χ²=1.965, P < 0.001), but the proportion of patients who needed to choose the second examination due to the unclear diagnosis in the first examination was lower(χ²=24.533, P < 0.001), diagnostic efficiency of fiberbronchoscopy+ROSE group was higher than that of fiberbronchoscopy group (Kappa: 0.411 vs 0.164; AUC: 0.904 vs 0.759). Conclusion ROSE technique can provide a clear cytological background and help to facilitate the etiological classification of pulmonary infection, compared with simple fiberbronchoscopy, the combination of fiberbronchoscopy and ROSE technique has higher diagnostic efficacy and can effectively reduce the number of second examination, it is worthy of clinical application.