Difficult-to-treat asthma is a complex disease with poor response to high-dose inhaled corticosteroids plus a second controller or need high levels of treatment to maintain control.Difficult-to-treat asthma represents a significant clinical challenge and a heavy medical burden due to its heterogeneity.Identification of the phenotypes and endotypes in difficult-to-treat asthma is very helpful for individualized therapy.This review summarizes the latest studies on the classification of difficult-to-treat asthma in order to provide evidence for the diagnosis and treatment of difficult-to-treat asthma in children.