An occupant protection system includes a winding shaft that winds up a seat belt; a reacher rotatably supported by a rotating shaft and which changes the position of the seat belt in a front-back direction of a vehicle; a biasing member biasing the reacher to turn in a front direction of the vehicle; a retraction detection unit detects that the reacher is in a rear position; a motor rotates the winding shaft in a winding direction and a pull-out direction of the seat belt; a current detection unit detects the motor current; and a control unit The control unit is configured to change the rotating direction of the motor to the pull-out direction when the motor is rotating in the direction of winding up the seat belt, the reacher is not in the rear position, and the motor current is a predetermined current value or higher.