Since the late 1970s, our department has been conducting animal experiments and has been using 5% cod liver oil sodium sclerosis for a long time in the clinical treatment of hemangioma. 5% cod liver oil sodium sclerosis as a sclerosing agent for the treatment of venous malformation, its mechanism of action is to promote the coagulation of proteins in the blood, promote platelet adhesion to the endothelial cells of blood vessels and the formation of thrombus, through thrombus mechanization to occlude the blood vessels and achieve the purpose of treatment. The therapeutic purpose is achieved through thrombosis and vascular occlusion. After the injection of sodium cod liver oil, the tumor turns purple-black, and the injection area becomes edematous and then shrinks and hardens, showing a solid shrinkage. On light microscopy, the intimal structure of the vessel lumen is unclear, the vessel wall is edematous and the lumen is bruised, mixed thrombus formation is seen, the vessel wall mechanism disappears in 1 to 2 weeks, smooth muscle is necrotic, collagen fibers are swollen, interstitial changes of the thrombus are seen in about 3 weeks, and extensive intra-tissue hemorrhagic infarction is observed. It is a simple, relatively safe and reliable treatment for deep venous malformations with no important surrounding tissue structures. As the chemical stimulation of the drug after injection causes sterile inflammation within the tumor, local swelling and painful reactions are obvious, oral hormonal drugs can be taken to reduce edema reactions and oral pain medication as appropriate. Injecting too shallowly can cause skin ulceration, and injecting into arteries can cause necrosis of blood supplying tissues. Long-term high-dose injection has certain toxic side effects on brain, liver and kidney. For patients before puberty, attention should be paid to deformities such as local developmental disorders caused by excessive treatment.