Objective: To investigate the diagnostic efficiency of chemiluminescent assay (CLIA) in mixed respiratory infection in children and adults, compare the pathogen spectrum and clinical characteristics of the two groups of people, and analyze the independent influencing factors of mixed infection. Methods: A total of 59 patients with acute respiratory virus infection admitted to the Xingguo People"s Hospital from November 2025 to October 2026 were selected and divided into children group (n=30, ≤14 years old) and adult group (n=29,>18 years old) according to age. All patients were tested for 8 common respiratory viruses using CLIA, and the multiplex PCR test results were used as the gold standard to calculate the detection rate of CLIA. Clinical characteristics of patients were collected, the differences in clinical characteristics between mixed infections and single infections were compared, and risk factors of mixed infections were analyzed using multivariate logistic regression. Results: The mixed infection rate among 59 cases was 25.42%(15/59), and the mixed infection rate in children group (36.67%) was significantly higher than that in adults group (13.79%)(P<0.05). The pathogenic spectrum of the children group was mainly influenza virus type A (FluA), Mycoplasma pneumoniae virus (MP), influenza virus type B (FluB), and adenovirus (ADV), while the adult group was mainly FluA, rhinovirus (HRV), and ADV. In mixed infections, the combination of FluA+MP, MP+ADV was the main combination in the children group, and the combination of FluA+HRV, FluA+ADV was the main combination in the adult group. The total detection rate of CLIA was 86.44%, and the detection rates for samples from children and adults were 90.00% and 82.76% respectively (P>0.05). For the detection of mixed infections, the detection rates in children and adults were 81.82% and 75.00% respectively (P>0.05). Multivariate logistic regression analysis showed that children and decreased lymphocyte count were independent influencing factors for the development of mixed infection (P<0.05). Conclusion: CLIA has high efficiency in detecting mixed respiratory virus infection in children and adults. Children are at high risk of mixed respiratory virus infection, and mixed infection is associated with more severe lymphopenia.