〔Abstract〕 Objective To investigate the efficacy of dandelion granule combined with azithromycin in the treatment of mycoplasma pneumoniae pneumonia (MPP) in children and its effect on T lymphocyte subsets. Methods 120 children with MPP diagnosed in Dongguan Kanghua Hospital from June 2019 to June 2020 were randomly divided into observation group and control group, with 60 cases in each group. The control group was treated with azithromycin, and the observation group was treated with dandelion granules on this basis. Both groups were treated for 14 days.The changes of peripheral blood T lymphocyte subsets in the two groups were detected before and after treatment, the improvement time of main symptoms and signs in the two groups were recorded, and the curative efficacy and safety of the two groups were evaluated. Results After treatment, compared with the control group, the improvement time of main symptoms and signs in the observation group were significantly shorter, the total effective rate and the improvement range of peripheral blood T lymphocyte subsets (CD3+ , CD4+ , CD8+ ) were significantly better, and the incidence of adverse reactions was significantly lower (P < 0.05). Conclusion Treatment of MPP in children with dandelion granule combined with azithromycin can increase the level of peripheral blood helper T cells (CD3+ , CD4+ ) , and decrease the level of inhibitory T cells (CD8+ ) , and enhance the body's immunity. It can relieve clinical symptoms and has good safety.