Abstract: A pyrotechnic cutting device (14) is designed for directly cutting one or two parts (10) made from a nonmetallic material, such as a composite material. The device (14) comprises a pyrotechnic expansion tube, which acts directly on the part or parts (10) to be cut, as well as an abutment (40) placed on the other side of the part and facing the spacer (20) installed alongside the tube. The abutment acts in the manner of an anvil during the use or operation of the pyrotechnic expansion tube (16). Thus, there is a clearly defined, well localized cutting of the part (10) along the edge (42) of the abutment aligned with the face (21) of the spacer (20) turned towards the tube (16).