Objective To investigate the timing of early naso-jejunum nutritional support on severe acute pancreatitis(SAP) patients and its feasibility and safety. Methods 72 patients with SAP were enrolled and randomized into experiment group and control group according to random number. EN (enteral nutrition) was administrated in the experiment group when the patients' circulation were relatively stable, abdominal distention decreased and the bowel sound could be heard; while EN was administrated in the control group when the patients' vital signs were stable, and peristalsis recovered with exhaust and sense of hunger, without obvious abdominal distention. The cultivation of secretions, hospital stay and overall cost of hospitalization were evaluated in the two groups of patients. Results The throat swabs, sputum culture, mid-portion urine culture of the two group were not significantly different. But the fecal culture in the experiment group was significantly lower than those of the control group (5.6% vs. 33.3%, P ＜ 0. 01); the hospital stay and overall cost of hospitalization in the experiment group was (26.0 ± 15.2)d and (78910 ± 77734)Yuan, which were significantly lower than those in the control group [(32.9 ± 22.3) d and (149528 ± 145936) Yuan, P ＜0.05]. Conclusions Appropriately bringing forward EN is safe and feasible, which can shorten clinical course and reduce the cost of hospitalization.