Objective To explore the epidemic characteristics of common pneumonia pathogens in preschool children in Xining area and analyze the influencing factors of progression to severe pneumonia. Methods A total of 522 preschool children with pneumonia who were treated in our hospital from May 2021 to March 2024 were retrospectively selected as the research subjects. Sputum samples from children were taken to identify the pathogens and analyze their pathogenic epidemic characteristics.According to the diagnostic criteria in the 2019 version of ^“Standards for the Diagnosis and Treatment of Community-Acquired Pneumonia in Children^”, determine whether it is severe pneumonia, and collect the clinical data of the children.Logistic regression was used to analyze the influencing factors of the progression of common pneumonia to severe pneumonia. Results Among the 522 children with pneumonia, 522 cases were infected with pathogens, of which 447 cases were single infection (85.63%), 75 cases were mixed infection (14.36%). A total of 597 pathogens were detected, including 257 viruses (43.05%), 240 bacteria (40.20%), 68 mycoplasma pneumoniae (11.39%) and 32 chlamydia pneumoniae (5.36) . The detection rates of Streptococcus pneumoniae (149, 24.96%) and respiratory syncytial virus (118, 19.77%) were higher. Logistic regression results showed that length of hospital stay (OR=2.235, 95% CI: 1.552-3.439), ICU admission (OR=2.426, 95% CI: 1.769-3.881), intestinal microbiota disorder (OR=1.626, 95% CI: 1.335-2.842), multi-drug resistance (OR=2.086, 95%CI 1.417-2.905), mixed infection (OR=3.134, 95% CI : 2.217-8.857), nutritional risk (OR=2.783, 95% CI: 2.038-4.764), CRP (OR=2.589, 95% CI: 1.805-4.117), PCT (OR=1.486, 95%CI: 1.077-1.649), and white blood cells (OR=1.329, 95% CI: 1.021-1.536) were all associated with the risk of severe pneumonia (P<0.05). Conclusion The main pathogens of pneumonia in preschool children in Xining are Streptococcus pneumoniae and respiratory syncytial virus. Paying attention to the treatment of children with intestinal disorders, multiple infections, and malnutrition is of great significance to improve the progression of pneumonia.