Objective To investigate the clinical value of high resolution multi-slice spiral CT in the diagnosis of severe pneumonia. Methods Retrospective analysis of CT data of 83 patients with severe pneumonia in our hospital from January 2013 to December 2015, and comprehensive analysis of high-resolution multi-slice spiral CT imaging features and pathological features. Results Among 83 patients, a total of 92 cases of complications including myocardial infarction, pulmonary infections, COPD, 48 cases(57.8%) are 1-2 organs involved, 35 cases(42.1%) are over 3 organs involved, and heart and kidney organs are mainly involved. Through CT scan and pathological diagnosis, among 83 patients, 54 cases accounted for 65.1% in the single and double lobes involved, 29 cases accounted for 34.9% more than three and three lung involved. 52 cases of community-acquired pneumonia (CAP), accounting for 62.6%, and 31 cases of hospital-acquired pneumonia (HAP), accounting for 37.4%. Conclusion High-resolution multi-slice spiral CT with multi-angle, wide-azimuth, high-resolution features, in the clinical diagnosis of patients with severe pneumonia, it is not only able to clearly show the relationship between pneumonia location, shape and the adjacent tissues, also clearly showed images of specific severe pneumonia, combined with clinical manifestations, which can quickly identify patients with severe pneumonia, which has significance clinical value in localization and qualitative of severe pneumonia, worthy of further promotion and application.