The invention discloses a power-driven gear-shifting executing mechanism which comprises an angular displacement sensor, a shell, a driving motor, a reducing mechanism, a support, a shaft sleeve, a rotation shaft and a controller used for receiving signals of a gear-shifting device and an electronic control unit of a vehicle. The shell is fixedly installed on the support, the driving motor, the reducing mechanism and the rotation shaft are installed inside the shell, the angular displacement sensor is fixedly installed outside the shell, one end of the rotation shaft is connected with the shaft sleeve, the shaft sleeve penetrates through the support and is used for being connected with a gear shifting crank of a speed changing box, the other end of the rotation shaft penetrates through the shell to be connected with the angular displacement sensor, the driving motor drives the rotation shaft through the reducing mechanism, and the controller is respectively connected with the angular displacement sensor and the driving motor. The power-driven gear-shifting executing mechanism has the advantages of being high in response speed, stable and reliable in performance, large in output torque, high in adjusting accuracy and the like, and electrical signal control over the gear-shifting motion of a traditional speed changing box is further achieved.