Obejective 11% of adults with diabetic ketoacidosis (DKA) also suffer from AP. The obejective of this research was to study the characteristics of AP with DKA, the factors related to the length of hospital stay, and to explore indicators for the severity of AP.Methods A retrospective analysis of 173 AP with DKA cases treated in our hospital from July 2011 to December 2020 was performed. We analyzed the gender, age, systemic inflammatory response syndrome(SIRS), pleural effusion, blood urea nitrogen(BUN), bedside index for the severity in acute pancreatitis(BISAP)score, white blood cell(WBC), aspartate transaminase (AST), lactate dehydrogenase(LDH), blood glucose, Ranson score, partial pressure of carbon dioxide (PaCO 2 ),triglyceride, modified CT severity index (MCTSI), potential of hydrogen potential of hydrogen (PH), amylase, glycated hemoglobin, C-reactive protein(CRP), creatinine(Cr), blood calcium, procalcitonin (PCT), the length of stay.Result Blood calcium, LDH, BUN, pleural effusion, MCTSI, Ranson score and BISAP score were related to the length of stay (P <0.05). WBC, AST, blood glucose, PaCO 2 , triglyceride, PH, glycated hemoglobin, CRP, Cr , PCT were not related to the length of stay (P> 0.05).Conclusion The current Atlanta classification is not suitable for evaluating the severity of AP with DKA. Serum calcium, LDH, BUN, pleural effusion, and MCTSI are suitable for evaluating the length of stay and severity of AP with DKA.