Tetracaine hydrochloride is a commonly used local anesthesia, its main feature is that it easily penetrates the mucosa, so it is often used for mucosal surface anesthesia, and can also be used for spinal block and nerve block. Common methods of tetracaine hydrochloride: topical local anesthesia, 1% solution spray or smear; infiltration local anesthesia, 0.025-0.03% solution; nerve block, 0.1-0.3% solution; epidural block 0.15-0.3% solution, When combined with lidocaine hydrochloride, the highest concentration is 0.3%; for subarachnoid block, 10-15 mg is mixed with cerebrospinal fluid and injected. It should be noted that infiltration of local anesthesia and nerve conduction block is the maximum amount of 0.1g used at a time.