We assessed the stabilization of an open-airway diameter and locally injected betamethasone for benign central airway stenosis using a prospective study to compare two treatment modalities: Conventional Interventional (CI) and CI combined Local Betamethasone Injected (LBI). The average optical density value for tumor necrosis factor β1 (TGF-β1) was compared in local airway tissues before and 7 d after CI and LBI treatments. Patient prognosis was recorded after one year of treatment. Eight patients were recruited from May 2013 to May 2016 and data show a significant statistical difference in TGF-β1 (94.57 ± 35.77 vs. 155.64 ± 47.38 (t=-7.591, P=0.000) before and after the CI treatment and before and after CI +LBI treatment (145.17 ± 39.38 vs. 84.65 ± 44.34 (t=8.536, P=0.000)). TGF-β1 was measured using ANOVA to compare treatments and there was a statistical difference between the two (F=128.568, P=0.000). Prognoses were effective (6/8, 75%), moderate (1/8, 12.5%), ineffective (1/8, 12.5%) and cured (7/8, 87.5%). Benign central airway therapy should include opening an obstructed airway and stabilizing the airway diameter as well as a local steroid injection to reduce TGF-β1 and minimize the negative effect of CI.