Feeding intolerance of enteral nutrition (EN) frequently occurs in patients with severe acute pancreatitis (SAP) because of intestinal motility disorders. Soluble dietary fiber (SDF) modulates the intestinal motility. The present study examined whether SDF can improve intestinal motility and permeability, and thereby reduce feeding intolerance, in patients with SAP. This study was a single-blind, randomized, controlled, single-center trial. Forty-nine patients with SAP were included. The control and SDF groups received the same EN solution via a nasojejunal tube. The SDF group additionally received 20-g/d polydextrose. The primary outcome was the time to reach the energy goal. Follow-up was continued for 28 days after admission or until discharge from the hospital. Among 49 randomized patients, 46 patients (n = 22, control group; n = 24, SDF group) were included in the intent-to-treat analysis. The time to reach the energy goal was 7.00 (6.00, 8.25) days and 5.00 (4.25, 6.00) days in the control and SDF groups, respectively (P < 0.001). The rates of feeding intolerance were significantly reduced in the SDF group (59.09% vs 25.00%, P < .05). SDF was associated with decreases in the incidence of abdominal distension (72.73% vs 29.17%, P < .01), diarrhea (40.91% vs 8.33%, P < .05), and constipation (72.73% vs 12.50%, P < .001). The time to first flatus and first defecation were significantly shorter in the SDF group (P < .001). The intestinal mucosal barrier function and levels of gastrointestinal hormone were improved by SDF, as evidenced by significantly reduced blood levels of diamine oxidase, D-lactic acid, endotoxin, and vasoactive intestinal peptide (P < .05). SDF shortens the time to reach the energy goal during EN and improves intestinal permeability and motility disorders, thus reducing the incidence of feeding intolerance in SAP patients. © 2020 American Society for Parenteral and Enteral Nutrition.