Objective To analyze the diagnostic value of combined detection of Mycoplasma pneumoniae immunoglobulin M (MP-IgM) antibody and MP-DNA for the diagnosis of Mycoplasma pneumoniae infection in children. Methods A total of 87 children suspected of Mycoplasma pneumoniae infection in our hospital from September 2023 to August 2024 were selected as the research object. All the selected children were tested for Mycoplasma pneumoniae IgM antibody and DNA. The results of MP-DNA, MP-IgM antibody and gold standard examination were compared, and the diagnostic efficiency of single and combined detection of Mycoplasma pneumoniae IgM antibody and DNA examination were compared.Results The gold standard diagnostic results showed that among the 87 children suspected of having mycoplasma pneumonia infection, 69 were positive and 18 were negative; 65 cases were diagnosed as positive and 22 cases as negative by the detection of mycoplasma IgM antibody, of which only 57 cases were true cases of mycoplasma pneumonia infection. The diagnostic sensitivity was 82.61% and the accuracy rate was 79.31%; in the 87 cases, 63 cases were diagnosed as positive and 24 cases as negative by MP-DNA testing. Only 58 cases were confirmed to have true mycoplasma pneumonia infection, with a diagnostic sensitivity of 84.06% and an accuracy of 81.61%; the combined detection of MP-DNA and MP-IgM antibodies resulted in 69 positive and 18 negative cases. Among them, only 66 cases were true cases of mycoplasma pneumonia infection, with a diagnostic sensitivity of 95.65% and an accuracy rate of 93.10%. Both were higher than those of single diagnosis, and the missed diagnosis rate was 4.35%, which was lower than that of single diagnosis, with a statistically significant difference (P<0.05). Conclusion The combined detection of MP-DNA and MP-IgM antibodies is more sensitive and accurate for the early diagnosis of mycoplasmal pneumonia compared to their single detection, providing important laboratory evidence for clinical mycoplasmal pneumonia infection and having high application value. By detecting MP-IgM antibodies and MP-DNA in children, it can assist clinicians in developing safe and effective treatment plans.