Objective To observe the changes of nutrition and immune function indices of patients with colorectal cancer using enhanced recovery after surgery.Methods A total of 64 patients with colorectal cancer admitted from March 2016 to March 2018 were divided into control group (n=33) and observation group (n=31).The patients in the observation group received enhanced recovery after surgery; the patients in the control group received conventional treatment.The nutrition indices (ALB,PA,and SF) and immune indices (IgA,IgG,and IgM) of the two groups before surgery and 1 day,3 days,and 7 days after surgery were detected.Results In the observation group,except for a lower level 1 day after surgery (P<0.05),no differences in PA level were observed between 3 days or 7 days after surgery and before surgery.In the control group,the PA,ALB,and SF 3 days after surgery had statistical differences compared with before surgery(P<0.05) and returned to the preoperative level 7 days after surgery.The changes of ALB,PA,and SF levels of the observation group were smaller than those of the control group (P<0.05).The postoperative immune function indices of both groups changed,and the levels 3 days after surgery were lower than before (P<0.05),and returned to the preoperative level 7 days after surgery.The changes of IgA,IgG,and IgM levels of the observation group were smaller than those of the control group as well (P<0.05).Conclusion Enhanced recovery after surgery could relieve the nutritional status and immune function of patients with colorectal cancer.