1. An electronic device comprising: a display screen having a preset screen size; a camera; at least one processor; and a storage device; wherein, the storage device stores one or more programs executable by the at least one processor; and wherein, one or more of the programs stored in the storage device cause the processor to: activate the camera to acquire a facial image of a user of the electronic device when the electronic device is activated; designate a facial zone of the acquired facial image; determine a size of the designated facial zone; acquire a distance from the user to the electronic device; calculate a ratio of the determined size of the designated facial zone and the preset screen size; determine whether the user is an adult based on the calculated ratio and the acquired distance; and deactivate the electronic device after a first determined duration when the user is determined not to be an adult.