The invention discloses an electric toothbrush. The electric toothbrush comprises a toothbrush head, a toothbrush handle, a motor, a controller and a light induction module, wherein the toothbrush head is connected with the toothbrush handle; a start switch is arranged on the toothbrush handle; the motor is used for driving the toothbrush head to move; the light induction module extends into and out of the oral cavity along with the toothbrush head; the light induction module is used for detecting environmental light, a signal is fed back to the controller if light exists, otherwise no signalis fed back; the controller is used for controlling at least two speed motions of the motor, the motor is driven to move at a first speed when the controller receives the signal fed back by the lightinduction module, otherwise the controller is used for driving the motor to move at a second speed; and the first speed is lower than the second speed. The electric toothbrush has the characteristic of power saving, and the toothbrush running speed is changed along with the tooth-brushing position change of a user.