The clinical value of combining the detection of Mycoplasma pneumoniae-specific antibody IgM, C-reactive protein, and procalcitonin in the diagnosis of Mycoplasma pneumoniae pneumonia in children is higher than single item detection, and it can provide a reliable clinical reference, as well as aid in evaluating the recovery effect of children, and it is worthy of application. Here, CD40LG is linked to Mycoplasma pneumoniae pneumonia.