A compound is shown in formula I and can be in the form of a pharmaceutically acceptable salt, or a stereoisomer, or a solvate, or a prodrug, or a metabolite. The compound takes effect rapidly and has a long-time local anesthetic effect following a single dose, with the sensory nerve blocking time being greater than the motor nerve blocking time, has both a long-acting local anesthetic effect and a selective local anesthetic effect, significantly reduces side effects of the compositions QX314 and QX314 and a quaternary ammonium salt compound with surfactant structural characteristics, and is safer. The compound of formula I of the present invention and a pharmaceutically acceptable salt thereof can be used for preparing drugs that have a long-time local anesthetic effect and a selective local anesthetic effect.