A pipe expanding plier is disclosed, and it includes a fixed handle, a movable handle, a mounting base, a pipe expanding head, and a pushing cone. One end of the pushing cone is provided with a rotating shaft, which is connected with the movable handle through a block. The mounting base is provided with a cavity. A gear ring, a gear ring shell and a shell reset element are provided in the cavity, and the gear ring is connected to the rotating shaft, and the gear ring is located in the gear ring shell, and a pawl assembly is provided in the gear ring shell, a reset block and a linkage block are provided on the gear ring shell, the shell reset element is arranged between the reset block and an inner wall of the cavity, and the linkage block extends out of the cavity to be matched with the movable handle.