The present invention relates to a method and an apparatus for preventing drunk driving. The apparatus comprises a drunk driving detecting unit, an automatic driving-limit unit, a warning module and a processing module, wherein the drunk driving detecting unit is electrically connected to the automatic drive-limiting unit, and the warning module is electrically connected to the processing module. The method comprises steps of: setting a first camera facing a driver, setting a second camera and a third camera facing a travel direction on a car body, and setting a fourth camera facing a direction against the travel direction on the car body. Thereby, the first camera detecting a variation of the drivers pupil, and a movement detecting module detects a swing magnitude and a swing frequency of the drivers body so as to control the car body and to limit driving, thus ensuring a driving safety.
