Botulinum toxin is a bacterial exotoxin produced by Clostridium botulinum during the growth and reproduction process. According to the different antigenicity of botulinum toxin, it can be divided into eight types A, B, C1, C2, D, E, F and G. The molecular masses of these toxins are all around 150 kD, with type A being the most virulent. Type A and B are the main types that have been developed for clinical use. Botulinum toxin type A is a polypeptide chain consisting of a heavy and light chain bound by a disulfide bond, which can be cleaved by proteases. type A botulinum toxin blocks neuromuscular transmission and causes flaccid paralysis by cleaving proteins necessary for acetylcholine release. Under normal conditions the muscle contraction process is: nerve impulse → acetylcholine (Ach) → end-plate potential → muscle action potential → muscle contraction. After injection the toxin binds to the receptor site of the cholinergic nerve terminal, the heavy chain of the toxin peptide chain binds to the unmyelinated region of the nerve terminal, the toxin itself enters the nerve membrane, acetylcholine is blocked by the light chain in the cytoplasm and cannot pass through the neuromuscular junction, the nerve no longer transmits Botulinum toxin type A does not block the transmission of nerve excitation, and there is no excitatory or conductive damage to nerves and muscles. The mechanism of Botox for wrinkles is that the facial expression muscles stop at the skin and directly pull the skin when they contract. The repeated contraction of these expression muscles is an important cause of power skin wrinkles. The repeated contraction of these expression muscles is an important cause of dynamic skin wrinkles. Botulinum toxin achieves wrinkle treatment by blocking neuromuscular transmission and inhibiting muscle contraction. Depending on the amount injected, the weak relaxation of the target muscles can occur as early as 24 h later, usually 48 to 72 h after toxin injection, with the peak effect usually coming after 7 to 14 days. This muscle relaxation is of limited duration, lasting approximately 3 to 6 months.