Objective: To observe and explore the value of the combined application of red blood cell distribution width (RDW), platelet distribution width (PDW), and immunoglobulin E (IgE) in the process of clinical diagnosis of children with asthma. Methods: Fifty-five children with suspected asthma were admitted to the hospital from July 2021 to July 2023. They underwent a bronchodilator test upon admission and their RDW, PDW, and IgE were detected. The efficacy of diagnosis with a single indicator (RDW/PDW/IgE) and combined parameters (PDW + PDW + IgE) were compared with the results of the bronchodilator test. Results: 49 cases of pediatric asthma were diagnosed by the bronchodilator test. RDW and PDW of asthmatic children were lower than those of non-asthmatic children, while the IgE of asthmatic children was higher than that of non-asthmatic children, and there was a significant difference in the RDW, PDW, and IgE among children with different degrees of asthma severity (P < 0.05). The positive rate of the three combined diagnostic tests of RDW, PDW, and IgE was significantly higher than the positive rate of a single-parameter diagnosis (P < 0.05). Conclusion: The combination of RDW, PDW, and IgE plays a crucial role in the clinical diagnosis of asthmatic children. These tests further improve the efficiency of clinical diagnosis and help identify the severity of the disease.