A head-mounted display device and a control method for an eye-tracking operation are provided. The head-mounted display device includes a frame, a track, a sensor and a controller. The track is disposed on a peripheral region of the frame. The sensor is disposed on the track, and is configured to capture a target image of a target area. The controller is coupled to the sensor, is configured to generate a control signal according to the target image, and adjust a position of the sensor on the peripheral region by moving the sensor according to the control signal.