To investigate the guidance role of preoperative nutritional risk screening in perioperative nutrition support for colorectal cancer patients in order to provide evidence for the rational clinical application of nutrition support. Nutritional risk screening was carried out in 290 hospitalized colorectal cancer patients from The Fourth People's Hospital of Wuxi City, Tongji Hospital of Tongji University and The Second Hospital of Soochow University with the nutritional risk screening(NSR) 2002 score summary table. Postoperative bowel function recovery and associated nutritional indices were compared between patients who received preoperative nutrition support according to the risk screening results and those who did not. Among 110 patients at nutritional risk, 65 received perioperative nutrition support and had faster recovery of intestinal function [time to first flatus (2.3±0.5) d vs. (3.3±0.5) d, time to first defecation (3.5±0.5) d vs. (4.6±0.6) d, semi-fluid intake (10.1±1.2) d vs. (12.4±2.2) d], shorter postoperative stay [(15.7±1.1) d vs. (18.8±1.4) d], and higher albumin, prealbumin and transferrin [(33.2±4.5) g/L vs. (26.0±4.0) g/L, (0.28±0.05) g/L vs. (0.16±0.04) g/L, (1.92±0.33) g/L vs. (1.75±0.45) g/L] at 7-day postoperatively (all P<0.05) as compared to those without perioperative nutrition support(n=45). While among 180 cases without nutritional risk, there were no significant differences in the above indices between patients who received preoperative nutrition support and those who did not (all P>0.05). It is important to evaluate the nutritional risk in hospitalized patients with colorectal cancer, and to carry out nutrition support actively for those at nutritional risk.