Objective To establish an early clinical warning model of infant community-acquired pneumonia progression to severe pneumonia based on the general situation, clinical manifestations and biological markers.Methods This study included 430 children hospitalized with pneumonia in the Maternal and Child Health Hospital of Inner Mongolia Autonomous Region from December 2022 to December 2024, and they were divided into two groups according to disease progression. Patients general conditions, symptoms and signs, laboratory examination indicators and other data were collected for statistical treatment and analysis, and a prediction model of infant CAP progression to severe pneumonia was constructed. Results The mild pneumonia group was generally older than the severe pneumonia group. WBC, N%, NLR, LDH, CRP, PCT, IL-6, SF, ALT, and D-dimer were higher in the severe pneumonia group than the mild pneumonia group; L%, ALB, CK, and immunoglobulin levels were higher than the severe pneumonia group. Conclusion Heart rate, NLR, LDH, CRP, D-dimer, and immunoglobulin M are independent risk factors for the progression of CAP to severe pneumonia. The nomogram model based on age, body temperature, heart rate, blood oxygen saturation, NLR, ALB, LDH, CRP, D-dimer, and immunoglobulin M has high predictive value