Surgical resection is still the standard of care for kidney cancer. Traditional resection of kidney cancer including Gerota’s fascia, perirenal fat and ipsilateral adrenal glands has been performed for nearly half a century. In recent years, with increased understanding of the biology of kidney cancer, more standardized tumor staging, and changes in patient classification, a more refined surgical approach has emerged, namely nephrectomy with maximum preservation of the renal unit, thereby improving the patient’s quality of life. Compared to radical kidney cancer surgery, kidney unit preservation surgery (NSS) is more challenging and requires a more refined understanding of the anatomical levels. Preoperative knowledge of the relationship between the tumor and the collecting system of the affected kidney and adjacent normal renal tissues, as well as the blood supply between the tumor and the affected kidney, is very important. Moreover, since the blood flow in the renal parenchyma is very rich and adjacent to the collecting system, how to maintain a clear intraoperative view and avoid postoperative complications such as bleeding and urinary leakage is the key to ensure the safety of surgery. In order to obtain a clear view during NSS surgery, it is better to completely block the renal blood flow. And in order to protect renal function, it is better to maintain normal blood flow to the kidney. In order to solve this contradiction, we propose the technical concept of complete renal tip block + ice crumb cooling, drawing on the technique of kidney transplantation. Under the protection of cooling by ice chips, the kidney can tolerate ischemia for 2 hours. In this way, the operator can comfortably suture the vascular stump and the open collecting system under a bloodless view, which greatly reduces the difficulty of the operation. Moreover, we used hemostatic gauze and fat to fill the renal defect, which effectively eliminated the dead space. After adopting this technique, we have performed more than 230 NSS surgeries, and only 6 cases had secondary bleeding. With the support of this technique, we also performed NSS surgery on 38 cases of central renal carcinoma, and there were no significant differences between the indices of surgical bleeding, postoperative complications, and postoperative residual renal function and those of peripheral renal renal carcinoma, except for the extended block time of (34±16) min. Applying the technical concept of complete renal tip block + ice crumb cooling broke through the original surgical exclusion zone and obtained a safety factor and treatment effect similar to that of peripheral renal cancer. Cooling in laparoscopic surgery with preserved renal units has been a difficult problem, and we completed a feasibility study of retrograde renal pelvis ice water perfusion to obtain renal hypothermia. It was found that after 15 min of continuous ice water perfusion, the renal parenchymal temperature in the perfusion group decreased from a minimum of 32.8°C to 23.8°C. And the surface ice addition group decreased from 33.2°C to 7.4°C at the lowest. The results suggest that the cooling rate of ice water by continuous retrograde renal pelvis perfusion is slow and the magnitude is not obvious enough. Later, when the perfusion was pressurized with a pressurized pump, the perfusion volume was significantly increased, and the magnitude of cooling was also increased. The experimental results have some clinical reference value. And we also used magnetic resonance three-dimensional angiography for anatomical assessment of the renal vasculature. When the anatomical information of renal vessels provided by preoperative MRA was compared with the real anatomical data intraoperatively, it was found that MRA showed 95% sensitivity of renal arteries and 97% accuracy of positive prediction, which could provide accurate information of arterial branches of the kidney, understand the presence of venous cancer thrombi, and show collateral circulation and dilated gonadal veins. Now, CTA and MRA examination has been established as a routine preoperative examination for NSS surgery in our department.