An electric toothbrush (100), comprising a brush handle (10) and a brush head (20), the brush handle (20) comprises an electromotor (21), a transmission assembly (22) and a transmission rod (23), the transmission assembly (22) comprises a main body (221), a gear (222), a connecting arm (223) and a positioning member (224), the electromotor (21) has a rotor engaged with the gear (222), the gear (222) is arranged with a connecting rod (225), which has an end fixed at an eccentric position of the gear (222) and another end arranged on the main body (221), wherein the connecting arm (223) has an end arranged on the connecting rod (225) and another end arranged on the positioning member (224), and the transmission rod (23) has an end running through the positioning member (224) and the main body (221) and extending to the brush head (10).