Asthma in babies requires the following tests: 1. Perform routine blood tests of the peripheral blood to check for eosinophils which can generally be increased to more than 6% and up to 20%-30% in children with atopic constitution, with an increased count of (0.4-0.6) × 10^9/L, sometimes up to (1.0-2.0) × 10^9/L; 2. Perform sputum examination, sputum cytology with a higher more eosinophils, usually greater than 2.5%, and can be seen with eosinophil degranulation; 3. Pulmonary function tests are performed to evaluate airflow limitation as well as reversibility and variability to check airway hyperresponsiveness. children over 6 years of age can undergo forceful pulmonary function tests, over 3 years of age can use pulse shock pulmonary function, and children younger than 6 years of age need to check tidal pulmonary function; 4. A bronchodilator test is performed at the same time as the pulmonary function test, which can reflect the degree of airflow restriction. Subjects can inhale a bronchodilator after completing forceful lung function; 5. Perform specific allergen diagnosis, including in vivo and in vitro tests; 6. Perform non-infiltrative airway inflammatory markers; 7. Rule out the diagnosis by imaging.