Tumor thrombus is one of the common complications of tumors, and refers to cancer cells in blood vessels or lymphatic vessels similar to blood clots, i.e., cancer cells clustering together, invading the vessels, and causing abnormalities in blood coagulation function, leading to disorders in blood circulation and abnormal coagulation with clustered cancer cells. Generally, the risk of tumor thrombus formation is very high, and patients with tumor thrombus have much worse treatment outcomes than those without. Renal cancer is also a tumor commonly associated with tumor thrombus. Once a tumor thrombus occurs, it indicates that the surgery might be staged quite late, and thus, its treatment results are also relatively poor.