Objective To study the diagnosis value of CT in the severity of acute pancreatitis. Methods In February 2014 to January 2015，there were 73 patients with acute pancreatitis treated in our hospital and all the patients underwent CT plain and contrast-enhanced scanning. We conducted retrospective analysis with these CT imaging data. Results Among all the 73 case, edematous pancreatitis were 64 cases, hemorrhagic necrotic pancreatitis were 9 cases. In the acute edematous pancreatitis cases CT scans, 9 cases did not see obvious exception; 14 cases of pancreas diffuse swelling; 7 cases of focal swelling; 26 cases of density and fuzzy with peripancreatic gap; 8 cases of the single effusion. In acute hemorrhagic necrotizing pancreatitis cases CT scans, 9 cases were lesser sac effusion; 4 cases of diffuse hemorrhage; 5 cases of focal hemorrhage; peripancreatic effusion in 6 cases; one case of kidney after a gap appears effusion; 2 cases effusion appears next to the left renal clearance. In necrotizing pancreatitis, pancreatic necrosis whole two cases, two cases of pancreatic head necrosis, two cases of necrosis segment, three cases of pancreatic tail necrosis. With dynamic enhanced CT scanning, the necrosis area was more significantly when compared with normal pancreatic tissue. Conclusion CT is of important diagnosis value in acute pancreatitis severity, especially for the diagnosis of acute hemorrhagic necrotizing pancreatitis, the enhancement CT with the advantages of simplicity, reliability, high sensitivity, etc.