Sputum can be used for the New Coronavirus nucleic acid test. Sputum is one of the samples that need to be collected for nucleic acid testing. In addition to nasopharyngeal swabs and oropharyngeal swabs, the main specimens collected for neo-coronavirus nucleic acid testing include bronchial lavage, alveolar lavage of lower respiratory tract specimens, and deep-cough sputum, with alveolar lavage having the highest detection rate. Collection of sputum can detect nucleic acids, and the detection rate is still high, but qualified deep-cough sputum specimens are more difficult to obtain. Deeply coughed sputum is a more difficult collection to perform. The sputum comes from the lower respiratory tract at the site of an infected lesion, and deep sputum is essentially non-existent in healthy people. The main component of the average person’s gently coughed up sputum is saliva, which is of poor significance, and only qualified sputum specimens are of testing significance.