If the pulmonary function test comes out to be moderate obstruction, it means that the flow rate is predominantly reduced, generally the percentage of 1 second respiratory volume is in the range of 40%-60%. Obstructive ventilation dysfunction occurs when the airway environment loses coordination with lung tissues during respiratory movement, resulting in insufficient opening or premature closure, leading to restricted flow of air in and out, and obstructive ventilation dysfunction occurs, which is clinically common in chronic obstructive pulmonary disease, bronchial asthma, wheezing bronchitis, pneumonia, etc. Further related tests are needed to clarify the diagnosis. Treatment is mainly etiological and symptomatic. For example, if the patient is found to have moderate obstruction caused by pneumonia, anti-infection treatment is needed. Pulmonary function tests are common tests of the respiratory system, and the main types of pulmonary dysfunction are obstructive ventilation dysfunction, restrictive ventilation dysfunction and mixed ventilation dysfunction. Obstructive ventilatory dysfunction is mainly based on flow rate, that is, the percentage reduction of 1-second exertional respiratory volume and exertional lung volume, and restrictive ventilatory dysfunction is mainly based on the reduction of lung volume, but mixed is both. The determination of the type of pulmonary dysfunction is mainly based on pulmonary function tests, and also needs to be combined with the patient’s clinical manifestations.