An aircraft pressurized cabin door (1) having an outer panel (2) and a door structure (3) including: two circumferential beams (4) fastened to the lateral edges of the door; a plurality of longitudinal beams (5a, 5b) which are arranged substantially perpendicularly between the circumferential beams (4) and are fastened to the outer panel (2), each longitudinal beam (5a, 5b) extending from one circumferential beam (4) to the other. At least one longitudinal beam (5b) is a beam that has a variable cross-section which increases from the ends (B, M) of the beam to the center (H, L) of the beam, with two bent support bars.