〔Abstract〕 Objective To evaluate the prognostic value of circulating tumor cell (CTC) detection in postoperative patients with colorectal cancer. MethodsA total of 99 patients with stage Ⅱ-Ⅲ colorectal cancer who were admitted to Yuebei People's Hospital from November 2018 to June 2020 were collected as the research objects. All patients underwent radical resection of colorectal cancer. 7.5 mL peripheral blood was collected for CTC detection 1 to 2 weeks after surgery before any postoperative adjuvant therapy, and another CTC detection was performed 6 months after surgery. According to the two CTC detection results, the patients were divided into group L (CTC < 3) (36 cases), group H (CTC ≥ 3) (34 cases) and group LH (CTC < 3 after surgery, CTC ≥ 3 after 6 months) (29 cases). Postoperative adjuvant therapy and follow-up were performed according to the National Comprehensive Cancer Network (NCCN) guidelines. The clinical data and prognosis of the three groups were compared.Results The recurrence, metastasis rate and mortality rate in the group L were lower than those in the group H and group LH, and there was no significant difference between the group H and group LH (P > 0.05). The median progression-free survival (PFS) was 32 months in the group L, 22 months in H group, and 24 months in the group LH, and the differences were statistically significant (P < 0.001). The median overall survival (OS) was 32 months in L group, 28 months in the group H, and 26 months in the group LH, and the differences were statistically significant (P = 0.018). However, there was no significant difference in PFS and OS between the group H and the group LH (P > 0.05). ConclusionCTC detection can be used as a prognostic factor in patients with colorectal cancer after surgery. Patients with normal CTC after surgery have higher PFS and OS than those with elevated CTC after surgery.