Objective To investigate the awareness of nutrition knowledge among colorectal cancer patients and to explore the effects of nutrition management on patients' nutrition. Methods From January 2016 to December 2016, we selected 80 colorectal cancer inpatients of internal and surgical department of oncology in Xuzhou Central Hospital as subjects by convenience sampling. The self-designed nutritional knowledge questionnaire for colorectal cancer patients was used to investigate their awareness of nutrition knowledge. All of the patients were divided into observation group (n=40) and control group (n=40) with the random number table. Control group received routine nutrition guidance. Observation group carried out whole-course nutrition management. And then, the nutrition of patients in two groups was compared before and after intervention. Results The awareness rate on nutrition knowledge of colorectal cancer patients was 60.0% (48/80) . There were statistical differences in the awareness rate on nutrition knowledge among patients with different ages, education, family history of colorectal cancer, whether it was the first case and whether they received nutrition education (P<0.05) . Patients' total serum protein, serum albumin and hemoglobin of observation group were higher than those of control group;the score of nutrition risk screening-2002 (NRS 2002) of observation group was higher than that of control group;the differences were all statistical (P<0.05) . Conclusions The awareness rate on nutrition knowledge of colorectal cancer patients is low. Strengthening nutrition management for patients will contribute to improving patients' nutrition and nutrition risk.