Induced sputum testing is a non-invasive test that reflects the nature and extent of airway inflammation and plays an important role in the diagnosis, treatment and prognosis of chronic airway diseases. This article outlines the development history of induced sputum technology, introduces the principle and operation of induced sputum technology, evaluates its safety, summarizes the three main test components, elaborates the role of this technology in various chronic airway diseases, such as reflecting the type of airway inflammation, predicting the efficacy of medication, and combining it with transcriptomics to study disease mechanisms, and briefly summarizes its innovations and makes a vision for the future.