【Abstract】Objective To investigate the effect of nutritional status and prognosis of perioperative immunonutritional support therapy on oral cancer patients with nutritional risk.Methods 60 cases of oral cancer patients with nutritional risk diagnosed in our hospital from September 2016 to September 2018 were selected as the research objects and randomly divided into observation group and control group, 30 cases in each group. The control group was given diet nutrition support and supplemented with nutrition education during the perioperative period, while the observation group was given immune nutrition regulation preparation on the basis of diet nutrition support during the perioperative period, and individualized nutrition support treatment was implemented according to the nutritional evaluation after operation. The changes of body mass index (BMI) and triceps skinfold thickness (TSF) were compared between the two groups on admission, the day of operation and the 7th day after operation. The laboratory indexes: serum prealbumin (PAB), serum albumin (ALB), transferrin (TRF) and total lymphocyte count (TLC) were compared. The incidence of abdominal distension, nausea, vomiting, diarrhea, surgical wound complications and length of hospital stay were compared between the two groups.Results At admission, there was no significant difference in BMI, TSF, PAB, ALB, TRF and TLC between the two groups (P＞0.05). There was no significant difference in BMI and TSF among the three time points (P＞0.05). PAB, ALB, TRF and TLC of the two groups were improved on the day of operation and the seventh day after operation, and the changes of each index in the observation group were more significant (P＜0.05). The incidence of gastrointestinal complications and wound healing complications in the observation group were significantly lower than those in the control group (P＜0.05), and the hospitalization time in the observation group was less than that in the control group (P＜0.05).Conclusion Immunonutritional support therapy for oral cancer patients with nutritional risk during perioperative period can improve nutrition related laboratory rapid change parameters, facilitate the postoperative recovery of patients, significantly reduce the length of hospital stay, and effectively reduce the incidence of postoperative gastrointestinal complications and wound-healing complications.