A method for washing and detoxifying a fresh animal liver and performing cell tissue preservation, said method comprising the following steps: rapidly extracting a completely fresh liver from an animal, removing the gall bladder, and retaining the first hepatic portal blood vessels; rapidly dissecting to find the portal vein, the bile ducts, the hepatic artery and the upper and lower ends of the inferior vena cava, and inserting a sterilised medical catheter into the portal vein, the bile ducts and the hepatic artery blood vessel; pouring a perfusion solution into the catheter, continually discharging macrophages and other immune cells containing a large amount of toxins, blood and harmful substances, and simultaneously removing bile via the bile duct system; when the fresh liver changes from blood red to white, extracting the catheter, and completing the treatment of the liver. The method ensures that the liver cell tissue suffers minimal damage, removes toxins, blood and harmful substances in the liver, and provides a health safeguard for the use of the liver as food at a later stage.