Occupational asthma refers to a new onset of asthma induced by a substance in the work environment or causes a recurrence of silent asthma (asthma that has resolved in childhood or over a long period of time). According to the different triggers are divided into allergen-induced OA and irritant-induced OA. more than 300 kinds of occupational allergens have been reported, occupational allergens are divided into high molecular substances and low molecular substances, common high molecular allergens are plant and animal proteins, cereals, fungi, etc.; low molecular allergens are organic or inorganic compounds, common are isocyanates, persulfates, rubber, aldehydes, drugs, etc. Allergen-induced OA occurs through exposure to allergenic substances with typical allergic reactions, similar to the pathogenesis of allergic asthma. Irritant-induced OA refers to airway dysfunction and asthma symptoms after inhalation of high concentrations of irritants, the onset of which is not related to allergy and refers to damage to airway epithelium by irritants and increased oxidative stress, resulting in an airway inflammatory response. Occupations at higher risk for occupational asthma include bakers, auto painters, hairdressers and woodworkers, firefighters, and cleaners. Every year, new occupational allergens are reported to be discovered. According to foreign epidemiological studies, OA accounts for more than 10% of all adult asthma and is the most common occupational lung disease. China began to implement the Diagnostic Criteria for Occupational Asthma (GBZ57-2002) on May 1, 2002, and the implementation of this standard has greatly promoted the epidemiological and clinical research of OA in China and standardized the means of diagnosis and prevention of OA in China. However, it is stipulated in this standard that the benefits for OA are limited to those who are directly exposed to the following five types of occupational wheezing agents, including: 1. vinegar isozolate; 2. phthalic anhydride; 3. polyamine curing agent; 4. platinum compound salt; 5. sisal. At present, the regulation has limited the epidemiological research and clinical control of OA in China to some extent. The overall study of OA in China lags far behind that of developed countries, and its reported incidence is much lower than the actual number of patients with the disease. Clinicians are often satisfied with the diagnosis and treatment of asthma patients in the process of diagnosis and treatment of asthma, while ignoring the relationship between occupation and asthma. The diagnostic criteria for OA are: 1) meeting the diagnostic criteria for bronchial asthma; 2) the presence of occupational asthma-causing agents in the work environment, and a causal relationship between occupational exposure and asthma onset; 3) no history of asthma before employment or silent asthma. The key aspect of the diagnosis is to establish a causal relationship between occupational exposure and the onset of asthma. The diagnosis of occupational asthma should be suspected in all adults with new onset or exacerbation of asthma, regardless of their history of definite occupational exposure, with questionnaires and appropriate laboratory diagnosis. Tertiary prevention measures can effectively reduce the incidence of OA and improve symptoms. Primary prevention emphasizes control of the environment and protective measures at work, replacing allergenic substances with non-allergenic substances as much as possible; secondary prevention emphasizes early identification of sensitive individuals, early diagnosis, and early removal from the allergenic environment. Drug treatment is the same as for asthma. The prognosis is related to the duration of exposure, the duration of symptoms before diagnosis, and whether or not the patient is a smoker, and most patients have significant improvement in their airway inflammation within 6 months after removal from the sensitizer.