The invention discloses a pre-pressing structure for bending and rebounding of flexible material and a pre-pressing method thereof. The pre-pressing structure comprises three assemblies; the first assembly is arranged on a transferring plate and comprises a first air cylinder, a motor, a bending plate and a pressure welding bottom block, wherein the first air cylinder is connected to the bending plate and controls the bending plate to move forwards or backwards, the bending plate is connected to the motor, the motor controls the bending plate to ascend or descend, and the front end face of the bending plate is connected to the pressure welding bottom block; the second assembly comprises a second air cylinder, and the second air cylinder is connected to a pressing plate; the third assembly comprises a third air cylinder, and the third air cylinder is connected to a pre-pressing head; the first assembly, the second assembly and the third assembly are located on the same air line, the transferring plate is connected to a motor assembly, the motor assembly drives the transferring plate to move between the second assembly and the third assembly, and the machining part on the first assembly is located right below the pressing plate or the pre-pressing head. According to the pre-pressing structure and the pre-pressing method thereof, machining is fast, the machining efficiency is improved, and the machining quality is obviously improved.