Mild asthma usually refers to grade 1 or grade 2 asthma, which mostly needs to be treated with glucocorticoids, β2-agonists, leukotriene receptor antagonists, theophylline drugs, etc. when asymptomatic and removed from allergens. 1. glucocorticoids: glucocorticoids mainly play the role of controlling bronchial inflammation, thus promoting normal bronchial ventilation and avoiding recurrent bronchial asthma attacks. Commonly used glucocorticoids include beclomethasone, budesonide, etc.; 2. β2-agonists: β2-agonists can diastole the bronchial tubes, thus improving asthma symptoms. The commonly used ones are salbutamol, terbutaline, salmeterol, formoterol, etc.; 3. Leukotriene receptor antagonists: they can achieve anti-inflammatory effect by regulating the biological activity of leukotrienes, and help to relax the bronchial smooth muscle, thus controlling asthma. Commonly used leukotriene receptor antagonists include montelukast sodium, zallust etc.; 4. Theophylline drugs: theophylline drugs can enhance the strength of respiratory muscle, enhance the clearing function of bronchial smooth muscle cilia, play the role of diastolic bronchial and anti-inflammatory, so as to improve asthma. Commonly used theophylline drugs mainly include aminophylline. The course of treatment for mild asthma is, in principle, to consider asthma step-down therapy after asthma symptoms have been controlled for at least 3 months and lung function recovery is maintained at a steady state. If the patient is on the lowest dose and no more asthma symptoms occur for 1 year, discontinuation of drug therapy may be considered.