The invention discloses a benzo-isoxazol piperidine derivative and an application in preparing analgesic and sedative medicaments. The compound has the antagonism of 5-HT2A and the mediation action of serotonin systems such as the reuptake inhibition of 5-HT, and the like. The derivative is the free alkali or salt of a compound having the structural general formula disclosed in the specification. Proved by pharmacological tests, the compound has good analgesic and sedative activities and smaller toxic and side effects. The structural general formula of the derivative is disclosed in the specification.