Vessel identification and dissection are the key processes of laparoscopic complete mesocolic excision (CME). Vascular injury will lead to complications such as prolonged operative time, intraoperative hemorrhage and ischemia of anastomotic stoma. Superior mesenteric artery (SMA), superior mesenteric vein(SMV), gastrointestinal trunk, left colic artery(LCA), sigmoid artery and marginal vessels in the mesentery have been found with possibility of heteromorphosis, which requires better operative techniques. Surgeons should recognize those vessel heteromorphosis carefully during operations and adjust strategies to avoid intraoperative hemorrhage. Preoperative abdominal computed tomography angiography(CTA) with three-dimensional reconstruction can find vessel heteromorphosis within surgical area before operation. Adequate dissection of veins instead of violent separation will decrease intraoperative bleeding and be helpful for dealing with the potential hemorrhage. When intraoperative hemorrhage occurs, surgeons need to control the bleeding by simple compression or vascular clips depending on the different situations. When the bleeding can not be stopped by laparoscopic operation, surgeons should turn to open surgery without hesitation.