A newly proposed method for the manufacturing of complex aluminum alloy automobile body panels is the rigid-flexible coupling forming process. The principle of this method is introduced and the key process parameters such as the hydraulic pressure loading path and rigid-flexible effect, blank holder force (BHF), and the draw bead setting are investigated by using numerical simulation and experiment. The relationship between the local rounded corner feature and the hydraulic pressure is theoretically analyzed specifically for the aluminum alloy inner panel of automobile engine hood. Meanwhile, the formability of this part is also surveyed in different parameters of the rigid-flexible coupling process. Finally, the applicability of the proposed method is validated by the results of experiments. The research exhibited that the rigid-flexible coupling forming process can be well used for manufacturing this kind of complex multi-feature sheet parts.