Budesonide inhalation therapy is effective for cough variant asthma (CVA), but the influencing factors are not well understood. This retrospective study assessed the clinical efficacy and influencing factors of budesonide inhalation therapy in 223 adult patients with CVA treated between January 2022 and February 2024. All patients received standard symptomatic treatment along with budesonide inhalation. The primary outcomes included lung function, serum inflammatory markers, and immune function, along with adverse reactions. Patients were divided into effective and ineffective groups based on treatment outcomes, and logistic regression was used to identify factors influencing treatment effectiveness. After treatment, lung function improved significantly, with increased forced expiratory volume, forced vital capacity, and peak expiratory flow. Additionally, serum levels of tumor necrosis factor-alpha (TNF-alpha), interleukin-4, and immunoglobulin E decreased. Immune function showed an increase in CD3+ and CD4+ cells, while CD8+ cells decreased. Adverse effects included nausea and indigestion in 5.83% of patients, drowsiness and fatigue in 4.04%, and throat discomfort in 3.14%. Based on the therapeutic efficacy evaluation after treatment, patients were divided into an effective group (n=188) and an ineffective group (n=35). Further multivariate logistic regression analysis revealed that older age (odds ratio [OR]=1.570), lower levels of 25-hydroxyvitamin D3 [25(OH)D3] (OR=0.798), and high levels of TNF-alpha (OR=1.850) increased the risk of reduced therapeutic efficacy. Budesonide inhalation therapy is effective for CVA patients, as it can improve lung function, reduce inflammation, and enhance immune function. However, factors such as age, 25(OH)D3, and TNF-alpha may influence the treatment outcomes.