Complex large kidney cancer refers to tumor diameter greater than 7 cm, accompanied by lymph node metastasis, surrounding organ invasion and vena cava thrombosis, which makes surgery bleeding and difficult. In order to reduce the difficulty of surgery and the incidence of complications, we have refined the “four key points” of surgery: improving the surgical exposure, preventing the dislodgement of cancer embolus, anticipating the bleeding site, and reducing the damage of neighboring organs, which has greatly improved the success rate of surgery for complicated large kidney cancer. We are the first in China to report the application of Omni hook in regional lymph node dissection of kidney cancer. The hook has the function of multi-joint adjustment and multi-angle pulling, which can greatly improve the intraoperative exposure and increase the safety of surgery. In the selection of surgical incision, it was found that the intraoperative complication rate of combined thoracoabdominal incision and abdominal L-shaped incision was lower than that of simple transverse incision or longitudinal incision. The subcostal transverse incision was better than the longitudinal incision in revealing the lateral and superior pole of the kidney. The combined thoracoabdominal incision is suitable for upper pole renal occupancy, especially on the right side. an L-shaped incision can satisfactorily reveal the middle and lower pole tumor, and with the assistance of an automatic pulling hook, the renal tip is located in the median area of the operative field, and the surgeon can easily complete the procedure. For tumor diameter >10cm or obvious enlarged lymph nodes in the renal hilum and displaced blood vessels, L-shaped incision is used; for huge occupancy in the upper pole of the kidney, combined thoracoabdominal incision is chosen. 2. Prevention of cancer embolus dislodgement Intraoperative cancer embolus dislodgement leading to pulmonary embolism is a fatal complication of kidney cancer surgery. For patients with high level cancer embolism, extracorporeal circulation assisted, deep hypothermic stop circulation or subdiaphragmatic block are often applied, but the trauma is huge and the hemodynamic impact is obvious. We borrowed a temporary venous filter from vascular surgery and placed it at the proximal end of the cancer embolus under DSA guidance before surgery, and successfully completed more than 20 cases of radical kidney cancer surgery with cancer embolus in the inferior vena cava, without any complication of cancer embolus dislodgement. 3. Foreseeing bleeding sites Through the summary of 89 cases, we found that the incidence of unexpected major bleeding in the inferior vena cava and its branches intraoperatively is high. In most cases, the vena cava bleeding is due to the tearing or avulsion of the fragile branches of the inferior vena cava at predictable locations, mainly as follows: (1) at the level of each lumbar vertebra, the lumbar veins converge laterally and posteriorly to the vena cava, and if the vena cava is drawn carelessly, it is easy to avulse the confluence of the lumbar veins and cause bleeding; (2) the first pair of lumbar veins sometimes converge behind the renal veins. (2) The first pair of lumbar veins sometimes converge behind the renal vein. When separating the renal vein in a large movement, failure to consider that the lumbar vein may be hidden behind it can lead to serious bleeding. (3) The right adrenal vein joins the inferior vena cava, which is brittle, thick and high, and must be carefully separated to avoid tearing; (4) The gonadal vein joins the anterolateral vena cava, and excessive traction on the vena cava near its confluence can easily lead to tearing and bleeding. The exact method of intraoperative hemostasis is proposed: pressure of the vena cava with the fingers towards the inner lower spine at the possible bleeding site is often effective in stopping the bleeding. The use of two Sim’s forceps, large and small, allows the bleeding to be sought and effectively controlled. When the tumor is large and it is difficult to free the vessels, it is difficult to complete the requirement of ligating the artery first and then the vein. The vein can be ligated first, and the distal end of the renal vein should also be sutured, otherwise the ligature line can also cause severe bleeding when it is dislodged. When the kidney and tumor obstruct the repair or treatment of the broken blood vessel, the tumor can be removed first to obtain the operating space. 4.Reducing adjacent organ injuries Liver and spleen injuries are more common during large kidney cancer surgery, mainly because the associated tether and ligament are not sufficiently free, and the force of the pull hook is directly transmitted to the brittle parenchyma of the liver and spleen, which is mostly lacerated. In addition, after cholecystectomy, the adhesions near the gallbladder fossa are serious, and it is very difficult to separate the hepatocolic ligament. To prevent liver injury, the right triangular ligament, coronary ligament and hepatic colonic ligament of the liver should be fully freed intraoperatively, and a good gauze block should be padded under the liver hook. To prevent spleen injury, the gastrocolic mesentery, splenic colonic ligament, and splenorenal ligament should be fully freed intraoperatively. To increase the upward freeing of the pancreas and spleen, the submesenteric vein should be ligated and disconnected near the splenic vein. Intraoperative pancreatic injury is due to the large size of the tumor and alteration of the normal anatomical position of the pancreas; sometimes the tumor grows infiltratively and separation between the perirenal fascia and the pancreatic envelope is difficult. It is worth noting that small injuries to the pancreas are sometimes difficult to detect. The tail of the pancreas and the spleen should all be carefully examined after left radical surgery to observe the free degree of the pancreas and the integrity of the envelope, and whether there is bleeding. If pancreatic injury is found, it is not advisable to simply repair the wound. Standardized resection of the tail of the pancreas can prevent the occurrence of postoperative pancreatic fistula to the greatest extent possible by leaving a double trocar in place and postoperative medication to inhibit gastric and pancreatic fluid secretion.