Objective To analyze the clinical and chest imaging characteristics of hospitalized patients with pertussis in Shenzhen Children's Hospital from January to March 2024, and explore the relevant risk factors for severe pertussis. Method Clinical and chest radiology data of 283 inpatients with pertussis hospitalized in Shenzhen Children's Hospital from January to March 2024 were collected. According to the severity of pertussis, they were divided into non-severe group (253 cases) and severe group (30 cases). The severe group patients were subdivided into survival group (25 cases) and death group (5 cases) according to clinical outcomes. Compare clinical indicators and radiology characteristics between these two groups, analyze risk factors for severe pertussis, and use ROC curves to analyze the predictive efficacy of different indicators and combined indicators. Result Toltaly 283 pediatric patients, among them 139 patients (49.1%)≤3 months old, 151 cases (53.4%) got a history of contact with cough patients, 117 cases (41.3%) had received the pertussis vaccine, Four cases (1.4%) had pertussis encephalopathy. Compared with the non-severe group, the severe group had higher index in percentage of onset age(≤3 months old),no vaccination, atelectasis, pulmonary arterial hypertension, respiratory failure, pertussis encephalopathy, invasive ventilation with respiratory machines, the use of blood exchange surgery and white blood cell count,neutrophil count, lymphocyte count, neutrophil ratio, CRP, lactate dehydrogenase, with statistically significant difference (P<0.05).Compared with the survival group, the death group had higher index in proportion with vomiting after coughing, neutrophil ratio, CRP and invasive ventilation with ventilators, with statistically significant difference (P<0.05). Age≤3 months, neutrophil ratio, CRP, atelectasis, and pulmonary arterial hypertension were related risk factors for severe pertussis. The ROC curve analysis results showed that the combined predictive sensitivity of age≤3 months, neutrophil ratio and CRP, atelectasis, and pulmonary arterial hypertension was 0.933, specificity was 0.762, and the area under the curve was 0.888 (95%CI 0.816-0.961) (P<0.001). Conclusion When the age of the patient was≤3 months, the proportion of neutrophils and CRP increased, and combined with atelectasis and/or pulmonary arterial hypertension, it is inclined to develop into severe illness. Monitoring blood routine and CRP can help evaluate the severity of the condition.