In a seat belt control device of the invention, when a buckle switch detects disengagement of a buckle and a tongue plate of a seat belt, the seat belt is retracted through a motor. In addition, the seat belt is re-retracted, through a motor, when a passenger detector detects that no passenger is present in an automobile, when a door switch detects that a door opens, or when an engine key switch detects that an engine key is pulled out or is in an off state. Thus, the seat belt can be positively retracted. Therefore, when a passenger gets off or is going to get off, the seat belt can be securely retracted to thereby prevent the seat belt from being caught by a projection in a compartment or by the door of the automobile.