Chlamydia pneumoniae (Cpn) is a kind of pathogenic microorganism transmitted through respiratory tract. It is a prokaryotic organism with unique development cycle. Chlamydia pneumoniae infection is an infectious disease caused by the bacterium Chlamydia pneumoniae that can lead to acute respiratory infections in children. In addition, it is also associated with many non-respiratory diseases, such as hepatitis, encephalitis, arthritis, Guillain-bar syndrome, cardiovascular disease and so on. Therefore, the detection of chlamydia pneumoniae is of great significance for the definitive diagnosis.