Liver cancer leg pain can be caused by bone metastasis, vascular embolism, tumor compression and other factors. It may also be caused by non-liver cancer accompanying factors, such as lumbar intervertebral disc herniation, leg trauma, lower limb venous blood return obstacle and so on. 1. Bone metastasis: When liver cancer develops into advanced stage, it is often accompanied by distant metastasis, such as bone metastasis, which can be manifested by pain in metastatic site, pathological fracture and local lumps. 2. Vascular embolism: when the cancer thrombus in the blood vessel falls and reaches the blood vessel of the lower limb with blood and causes embolism, unilateral swelling and pain of the lower limb can appear. 3. Tumor compression: after the tumor has metastasized to the pelvis or abdominal cavity, with the development of the tumor, it can lead to the compression of venous return; or after it violates the nerves, it can cause leg pain. 4. Non-tumor factors: such as herniated lumbar intervertebral disc, leg trauma, venous blood return obstacle in lower limbs, phlebitis and other factors can also cause leg pain. For serious cases, it is recommended to consult doctor to clarify the cause of the disease and carry out targeted treatment.