Application of dexmedetomidine combined with sufentanil in colon cancer resection and its effect on immune and coagulation function of patients was studied. Colon cancer cases (n=176) admitted to Xiangya Hospital Central South University were selected into the study. They were divided into group A (n=92) and group B (n=84). In group A, patients underwent surgery anesthesia with dexmedetomidine combined with sufentanil. In group B, patients underwent surgery anesthesia only with sufentanil. The anesthesia induced intubation, operation time and incidence of postoperative adverse reaction of patients were compared between the two groups. Heart rate (HR), systolic blood pressure (SBP) and diastolic blood pressure (DBP) were observed and recorded before induction, before intubation and after intubation. Blood coagulation analyzer was used to detect four items of coagulation before and after operation. FACSCalibur flow cytometry was used to detect T lymphocyte subsets in peripheral blood of patients in the two groups. The pain scores (VAS) of patients in the two groups were measured and recorded after surgery at 4, 24 and 48 h. There was a difference in anesthesia induced intubation and operation time of patients in both groups (P<0.05). There were differences in HR, SBP and DBP of patients in both groups after intubation (P<0.05), in postoperative coagulation function (P<0.05), and in postoperative immune function of patients in both groups (P<0.05). The VAS scores of patients in both groups were different at different time-points after operation (P<0.05). There were differences in postoperative adverse reactions of patients in both groups (P<0.05). Dexmedetomidine combined with sufentanil is a viable anesthetic regimen for colon cancer resection. The coagulation function and immune function have certain improvement effect for patients.