Occupant restraint device for vehicle

An occupant restraint device for a vehicle, comprising:

• a seatbelt configured to restrain an occupant sitting on a vehicle seat, at the vehicle seat;
• and
• a belt backing airbag configured to, when gas is supplied to the belt backing airbag from an inflator at a time of frontal collision of the vehicle, inflate and expand between at least a shoulder belt of the seatbelt and a shoulder area of the occupant, the belt backing airbag configured to move along the shoulder belt together with moving to a vehicle front side to follow the occupant moving to the vehicle front side due to inertial force, and the belt backing airbag configured to maintain a state in which the belt backing airbag is interposed between at least the shoulder area of the occupant and the shoulder belt,
• wherein the belt backing airbag is linked to the vehicle seat or a vehicle body via a cord-shaped member that is resiliently deformable, the cord-shaped member configured to extend to follow movement of the occupant to the vehicle front side.