The acute toxicity of sodium benzoate is less, and the maximum non-effect dose (MNL) of animals is 500mg/kg body weight. However, it can be converted into highly toxic benzoic acid in the acidic environment of the human intestinal tract. Ingestion of benzoic acid and its sodium salt in mice can cause weight loss, diarrhea, bleeding, paralysis and even death. The toxicity of benzoic acid is achieved by changing the permeability of the cell membrane, inhibiting the absorption of amino acids by the cell membrane, and inhibiting the activity of enzymes such as lipase through the cell membrane, thereby hindering the synthesis of ATP.