The present invention provides a tongue training device, which includes an elastic body, a displacement sensor and a wireless communicator. Wherein, the elastic body has a tongue inlet and an accommodating space in communication with the tongue inlet, so as to accommodate a part or a whole of the tongue of the user in the accommodating space. The displacement sensor is disposed on the elastic body to sense the displacement distance and the displacement direction of the elastic body, and generate the corresponding displacement distance signal and displacement direction signal. And, the wireless communicator is disposed on the elastic body, connects the displacement sensor and the external device, and transmits the displacement distance signal and the displacement direction signal to the external device, so as to operate the external device according to the displacement distance signal and the displacement direction signal.