An electronic toothbrush, comprising: a brush head (1), an ultrasonic vibration motor (2), a housing (3), an upper sliding cover (4), a lower sliding cover (5), a lower housing (6), a flip cover (8), a screw (9), a variable-speed motor (10), a high-frequency switch (14), an on-off button (15) and a control panel (16). The ultrasonic vibration motor (2) is drivingly connected to the brush head (1), the variable-speed motor (10) is drivingly connected to the screw (9), the upper sliding cover (4) and the lower sliding cover (5) are slidably internally connected at an inner side of housing (3), and the ultrasonic vibration motor (2) is connected between the upper sliding cover (4) and the lower sliding cover (5)； the screw (9) drives the upper sliding cover (4), the lower sliding cover (5), the ultrasonic vibration motor (2) and the brush head (1) to move up and down in the housing (3). The variable-speed motor (10) and the screw (9) are used to drive a main body structure composed of the upper sliding cover (4), the lower sliding cover (5), the ultrasonic vibration motor (2) and the brush head (1) to slide up and down within the housing； when in use, the main body structure moves upward, the brush head (1) extends out of the flip cover (8) such that a user may brush his or her teeth； after use, the main body structure is retracted downward into the housing so as to protect the brush head (1).L'invention concerne une brosse à dents électronique, comprenant : une tête de brosse (1), un moteur à vibrations ultrasonores (2), un boîtier (3), une protection coulissante supérieure (4), une protection coulissante inférieure (5), un boîtier inférieur (6), une protection rabattable (8), une vis (9), un moteur à vitesse variable (10), un commutateur haute fréquence (14), un bouton marche-arrêt (15) et un panneau de commande (16). Le moteur à vibrations ultrasonores (2) est relié par entraînement à la tête de brosse (1), le moteur à vitesse variable (10) est relié par entraînemen
