The invention discloses a
stringer assembly, a stiffened
wall plate, a stiffened
wall plate assembling method and an aircraft, and belongs to the technical field of
aircraft manufacturing. The
stringer assembly comprises a cap-shaped
stringer and a forming die, the cap-shaped stringer comprises a stringer main body and a
lap joint part, the stringer main body extends in the first direction and is provided with a cavity, the forming die comprises a containing part extending in the first direction, the containing part is provided with a containing groove, and the
lap joint part is provided with a
lap joint part. The containing groove extends in the first direction and is opened in one side of the second direction, the containing groove and the opening of the cavity face the same direction, the stringer body penetrates through the opening of the containing groove and is installed in the containing groove, the end, in the first direction, of the containing groove is closed, and the lap joint part is in lap joint with the forming mold. The cap-shaped stringer is blocked by the closed end of the containing groove of the containing part, it is guaranteed that the cap-shaped stringer cannot penetrate through the containing part and pass through the net size area in the
skin, the influence on the surface quality of the
skin is reduced, and the forming die cost is reduced.