A 58-year-old male patient was incidentally found to have a tumor of 8 cm in diameter in his left kidney by ultrasound during a physical examination this year, and then CT showed a possible malignant tumor, i.e. renal cell carcinoma (renal cancer for short). After repeated consideration, the patient and his family wished to perform the surgery of removing the tumor and preserving the kidney at the same time. After coming to our hospital, through the arterial CT angiography of the kidney, we found that although the tumor exceeded the conventional limit of 4 cm for traditional kidney-preserving surgery, there was still some room for operation between the tumor and the renal vascular trunk, so we explained to the patient’s family the feasibility and risks of using laparoscopy as a minimally invasive means to perform tumor resection + kidney-preserving surgery (NSS). The family chose this surgical approach. The tumor was completely resected and the left kidney was preserved. The intraoperative tumor diameter was measured to be 8 cm and the postoperative pathology report was renal clear cell carcinoma. The patient was discharged from the hospital on the fourth day after surgery. According to the latest international academic consensus in the past two years, (laparoscopic) tumor resection + kidney preservation surgery for renal cancer larger than 4 cm has gained more evidence-based support and affirmation, and its postoperative tumor recurrence rate and tumor-free survival rate are not statistically different from those of nephrectomy, and the incidence of chronic kidney disease (CKD) is significantly lower than that of nephrectomy, which is important for improving the quality of patients’ survival. It is of great significance to improve the quality of survival. Therefore, there is a growing consensus to perform (laparoscopic) tumor resection + kidney preservation surgery for renal cancer larger than 4 cm. The current difficulty is that the tumor resection + kidney preservation surgery (NSS) for kidney cancer larger than 4 cm is technically difficult even for open surgery, and the minimally invasive laparoscopic procedure is even more challenging for the surgeon, because while ensuring complete resection of the tumor, the operation of kidney suture and reconstruction must be completed within the limited time limit of thermal ischemia, which is arguably the most severe psychological and technical requirement for the urologist. This is the most severe psychological and technical requirement for urologists.