Rubber bladder forming is one of sheet metal forming methods for aircraft sheet metal parts. The estimation approach of initial blank outline is a difficult task during the forming die design stage, especially the rubber bladder forming manufacturing. In accordance with the technologic characteristics of rubber bladder forming, a fast and accurate estimation approach is proposed for the initial blank outline of rubber bladder formed part based on the one-step inverse forming finite element method. The friction influential effect between the rubber bladder and sheet metal can be considered by the equivalent external force. Firstly, the designed aircraft sheet metal part is treated as the final configuration of one-step inverse analysis; then a quick reverse simulation is carried out to obtain the initial blank mesh by the one-step inverse finite element method. Finally, the blank outline from the above initial blank mesh is applied to real rubber bladder forming manufacture. The experiment and comparison r...