Pancreatic exocrine insufficiency (PEI) secondary to chronic pancreatitis seriously affects the quality of life of the patients. There is no single and widely used method for diagnosis of PEI. Diagnosis of PEI should be based on the clinical manifestations, pancreatic exocrine function tests, nutritional status and other aspects. Pancreatic enzyme replacement therapy (PERT) is the main treatment of PEI, which should be combined with improved nutritional status and lifestyle. Therapeutic effect should be monitored during PERT by observing the clinical manifestations, detecting the content of serum nutrients and so on. For the patients with poor prognosis after PERT, it is necessary to carefully analyze the causes to formulate a reasonable countermeasure.