Abstract: The fastened seatbelts cutting device for transport vehicle, especially automotive vehicles, featuring bushing-shaped housing with an explosive charge or a gas generator inside, the charge and generator connected with a system activating the belt cutting drive, also featuring a cutting knife and a slot for this knife or blade and a slot to house the belt being cut, has a pusher (6) located between the gas generator (4), chamber (3), and the cutting segment (7), sealed with respect to the working chamber (8) in the guide chamber (5), and the blade (9) cutting edge (21) is one of the sides of triangle connected with the blade (9) body seated in the cutting segment (7).