Provided are a method and apparatus for preventing an illegal attack, and an electronic device. According to one embodiment, the method comprises: when a user feature of a user is identified successfully, determining whether a living body detection result for the user feature indicates failure; if the living body detection result for the user feature indicates failure, locking a feature ID when the feature ID of the user feature is not locked and a locking condition of the feature ID is satisfied currently; and if the living body detection result for the user feature indicates success, unlocking the feature ID when the feature ID of the user feature is locked and an unlocking condition of the locked feature ID is satisfied currently.