This application provides an electronic device and a control method for a movable assembly. The electronic device provided in this application includes a movable assembly. An optical proximity sensor is disposed on the movable assembly. The movable assembly may be spaced from a fixed assembly on the electronic device, and the movable assembly can move on a plane that is disposed in parallel relative to the fixed assembly. A light intensity of light that is from the optical proximity sensor and that is reflected by the fixed assembly may reflect a position of the movable assembly relative to the fixed assembly. According to the control method for a movable assembly in this application, whether the movable assembly moves to a specified target position may be determined based on the light intensity of the light that is reflected by the fixed assembly and that is detected by the optical proximity sensor.