There is no doubt that surgery is one of the most important means of treating tumors. However, not all patients require surgery immediately after diagnosis. Many surgeries are hastily performed without thorough and rigorous evaluation, only to find that the tumor cannot be removed intraoperatively, or that the patient dies of perioperative complications after the surgery is done. Therefore, it is necessary to rigorously evaluate and clarify the indications and contraindications for surgery, discuss with the anesthesiologist in advance to make preoperative preparations, and fully communicate with the patient’s family members about the problems that may arise during and after surgery. For patients with tumors, such as distant metastasis, old and weak patients who cannot tolerate surgery, poor general condition with malignant clinical manifestations, combined with important organ dysfunction, etc., immediate surgery is not suitable. For those tumors with large local tumor size or regional metastasis, which cannot be completely resected by immediate surgery, it is necessary to seek for individualized and optimal comprehensive treatment plan through multidisciplinary consultation, such as medical oncology, surgical oncology, radiotherapy, pathology and imaging. For earlier tumors, surgical resection can be curative. In recent years, with the improvement of the efficacy of chemotherapy (radiotherapy), it has been proved that for patients with locally advanced tumors, several cycles of chemotherapy (radiotherapy) before undergoing surgery can reduce the size of local foci, downstage the tumors, increase the resection rate of surgery, reduce the risk of recurrence and metastasis, improve progression-free survival, and ultimately prolong the overall survival, so as to provide patients with the greatest benefits. For patients with distant metastasis, if it is a single isolated metastatic lesion, receiving systemic therapy while systematically resecting the metastatic lesion and the primary tumor lesion, it is also expected to achieve a better therapeutic effect. Currently, the more successful preoperative chemotherapy includes breast cancer, lung cancer, osteosarcoma, rectal cancer, esophageal cancer, gastric cancer, etc., which increases the chance of organ preservation (e.g. breast preservation, limb preservation, anal preservation, etc.). In addition, preoperative chemotherapy can assess whether the tumor cells are sensitive and effective to the chemotherapy regimen, provide the best basis for the development of postoperative adjuvant chemotherapy regimen, maximize the effect of chemotherapy, and achieve the purpose of curing the tumor. Therefore, the discovery of tumor should be under the guidance of professional doctors to develop the most appropriate treatment plan, rather than simply everything.