Objective To investigate the relationship between the expression of miR-30 in peripheral blood and airway inflammation indexes and the severity of asthma.Methods 80 patients with acute exacerbation of asthma admitted to our hospital between January 2021 and June 2023 were selected as the observation group as well as 80 patients from the population with health check-ups during the same period as the control group.The observation group was divided into mild group(n=28),moderate group(n=34),and severe group(n=18)based on the severity of the condition.The levels of miR-30 in peripheral blood and airway inflammation indexes[Transforming growth factor β1(TGF-β1),Interleukin 6(IL-6),interleukin-33(IL-33),tumor necrosis factor-α(TNF-α)]were measured in the observation group and the control group.The expression of miR-30 in peripheral blood of patients with asthma and its correlation with airway inflammation were analyzed.Results Comparison of miR-30,TGF-β1,IL-6,IL-33,and TNF-α between the observation group and the control group,the difference was statistically significant(P<0.05).Comparison of miR-30,TGF-β1,IL-6,IL-33,TNF-α,eosinophilic granulocyte(EOS),and exhaled nitric oxide(FeNO)levels in the three groups of the mild,moderate,and severe groups,the difference was statistically significant(P<0.05).The correlation analysis showed a positive correlation between peripheral blood miR-30 and the levels of TGF-β1,IL-6,IL-33,and TNF-α(r>0,P<0.05),and Logistic regression analysis showed that peripheral blood miR-30,TGF-β1,TNF-α,FeNO,and EOS were the influencing factors for the degree of asthma disease condition(P<0.05).Conclusion Peripheral blood miR-30 exhibits abnormally high expression in asthma patients and is closely related to airway inflammation indicators.The high expression of miR-30 and the increase of airway inflammation index may aggravate the severity of asthma.High expression of miR-30 may exacerbate the severity of asthma.