Abstract: Objective: This study aimed to analyze imaging and clinical data of patients with severe and critical coronavirus disease 2019 (COVID-19) with different prognoses and provide help for clinical decision-making. Method: Clinical data and chest imaging computed tomography (CT) of patients with severe and critical COVID-19 were collected. Clinical data included: blood routine indexes, C-reactive protein, procalcitonin (PCT), the indexes of liver and kidney function, D-Dimer, myocardial enzyme, B-type amino terminal natriuretic peptide (LNTP), and whether there was any underlying medical history. The chest CT images and various indexes of patients with different prognoses of COVID-19 were compared. The relevant indicators with significant differences between the two groups were analyzed using binary logistic regression. Results: A total of 118 patients were enrolled, including 68 in the death group and 50 in the survival group. The age of the death group was longer, and the proportion of sputum and poor tolerance was higher than that of the survival group. Compared with the survival group, in the death group, there was a higher abnormal proportion of leukocyte count (WBC), neutrophil absolute value, monocyte absolute value, red blood cell count (RBC), hemoglobin, erythrocyte ratio, abnormal glomerular filtration rate, PCT, D-Dimer, creatine kinase isoenzyme (CK), troponin (TNI), LNTP. Compared with the survival group, WBC, NEUT and percentage, neutrophil/lymphocyte ratio, erythrocyte volume distribution width, erythrocyte volume distribution width standard deviation, PCT, D-Dimer, CK, CK-MB, myoglobin (MYO), TNI and LNTP were significantly increased in the death group, while the lymphocyte percentage, monocyte percentage, mean RBC hemoglobin concentration (MCHC), and glomerular filtration rate were significantly lower. Compared with the survival group, there was no significant difference in the imaging signs of COVID-19 infection in the death group, but the scope of initial chest CT lesions was larger, with more than 50%. In the survival group, more CT lesions were located in the periphery of the lung and subpleura, while in the death group, more lesions showed progression or aggravation. Age, RBC, glomerular filtration rate, CK-MB, MYO, and LNTP were the main factors that suggested prognostic outcomes. Conclusion: Age, blood routine, liver and kidney function, myocardial function, hemagglutination status, inflammatory reactant index, and lung lesion extent and progression of patients infected with COVID-19 are important factors indicating the severity of the disease and poor prognosis. Abnormal increases in leukocyte and neutrophilic granulocyte, CRP, PCT, D-dimer, and myocardial markers might be the main factors that better predict fatal outcomes in severe and critical patients. Abnormalities in age, RBC, glomerular filtration rate, CK-MB, MYO, and LNTP were the main factors indicating fatal outcomes in severe and critically ill patients. Combined with the comprehensive evaluation of clinical and laboratory examinations, imaging findings and follow-up are indispensable methods to evaluate the severity and prognosis of the disease.