Objective: To evaluate the safety, feasibility and short-term efficacy of totally laparoscopic left colectomy for left colon cancer by using overlapped delta-shaped anastomosis technique for digestive tract reconstruction. Methods: A retrospective cohort study was conducted to collect the clinical data of 86 patients with left colon cancer who underwent laparoscopic surgery in Cancer Hospital of Chinese Academy of Medical Sciences from October, 2017 to February, 2019. The patients were divided into totally laparoscopic left-sided colectomy (TLLC) (treatment group, n=25 cases) and laparoscopic-assisted left-sided colectomy (LALC) (control group, n=61 cases). The intraoperative and postoperative data were compared between the two groups. Results: There were no surgical-related deaths in both groups. All the patients in the TLLC group underwent laparoscopic resection, while one patient in the LALC group transfer to open surgery. The operation time in TLLC group and LALC group were (164.5±42.3) min and (171.0±43.1) min, respectively, without statistically significant difference (P=0.516). However, the intraoperative blood loss of patients in the TLLC group was (36.4±22.7) ml, which was significantly less than (52.9±32.2) ml in the LALC group (P=0.026). The anastomosis time in the TLLC group was (39.1±6.5) min, which was significantly longer than (24.9±5.4) min in the LALC group (P<0.001). Postoperative exhaust time in the TLLC group was (2.6±0.5) days, which was significantly shorter than (3.3±0.8) days in the LALC group (P<0.001). The incision length in the TLLC group was (4.2±2.2) cm, significantly shorter than (7.0±2.5) cm in the LALC group (P<0.001). The length of the resected bowel was (21.0±7.3) cm in the TLLC group, which was significantly longer than (17.5±5.4) cm in the LALC group (P=0.037). The length of hospital stay in the TLLC group was (6.2±1.9) days, which was significantly shorter than (7.9±1.5) days in the LALC group (P<0.001). The incidences of postoperative complications in the TLLC group and LALC group were 0 and 4.9% (3/61), respectively, without statistically significant (P=0.553). No anastomotic complications occurred in both groups. During the follow-up period, neither group of patients was hospitalized again, and no tumor metastasis or recurrence occurred. Conclusions: It is safe and feasible to apply the TLLC with overlapped delta-shaped anastomosis in patients with left colon cancer. It has better short-term effects such as shorter incisions, faster recovery, and shorter postoperative hospital stays, and is worthy of further promotion.