Objective To analyze the clinical pathogenic characteristics of children with co-infected pneumonia, and to provide reference for clinical diagnosis and treatment. Methods Children with co-infected pneumonia treated in the pediatrics department of the First Affiliated Hospital of Chengdu Medical College between June 2023 and May 2024 were selected. According to age, the children were divided into goups of infants, toddlers, preschoolers, school-aged children, and adolescents. The clinical pathogenic characteristics of children with pneumonia were analyzed. ResultsA total of 358 pediatric patients were included. Among them, there were 189 males (52.79%) and 169 females (47.21%); 71 (19.83%) were infants, 74 (20.67%) were toddlers, 113 (31.56%) were preschoolers, 75 (20.95%) were school-aged children, and 25 (6.98%) were adolescents. There was no statistically significant difference in the composition of males and females among different age groups or types of pneumonia (P>0.05). The bacteria detected were mainly Haemophilus influenzae, Staphylococcus aureus, Moraxella catarrhalis and Streptococcus pneumoniae. Viruses in the pathogen mainly included adenovirus, influenza A and B stream, human rhinovirus and respiratory syncytial virus. The main atypical pathogen detected was Mycoplasma pneumoniae (240 cases). Except for atypical pathogens (P>0.05), the detection rates of bacteria and viruses among different age groups showed statistically significant differences (P<0.05). The compositions of bacterial co-infections, viral co-infections, bacterial+viral infections, and co-infections involving atypical pathogens were compared among different age groups, and the difference was statistically significant (P<0.05). The proportions of different types of pathogens detected in winter were the highest. Conclusions Children with co-infected pneumonia are mainly aged 0-6 years old. The incidence of co-infected pneumonia in children is the highest in winter. Mycoplasma is the main pathogen in dual infections or co-infections. Co-infections in early childhood are mainly caused by bacterial infections, and the incidence of viral infections increases with age.