The invention discloses a forming device and a forming method for a pipe with a small bending radius, and relates to a pipe forming device and a pipe forming method. With the adoption of the forming device and the forming method, the shortage of the existing forming technology of the pipe with the small bending radius is overcome. The scheme of the device is as follows: one end of a second mandrel is arranged in a first tube blank; the other end of the second mandrel is arranged in a second tube blank; one end of a first mandrel is arranged in the first tube blank; one end of a third mandrel is arranged in the second tube blank; the other end of the first mandrel is arranged in a first punch; the other end of the third mandrel is arranged in a second punch; the first tube blank, the second tube blank, the first punch and the second punch are arranged in a mould cavity; and a second mandrel positioning bulge is arranged in a corresponding ring groove. The scheme of the method comprises a filling stage and a forming stage. The forming device and the forming method are used for pipe forming.