The invention belongs to the field of supporting-disk piles, and provides a supporting-disk pouring pile and a forming device thereof. The forming device of the supporting-disk pouring pile comprises an extrusion-expansion assembly, and a lengthening rod, wherein the extrusion-expansion assembly comprises a hydraulic jack and a propelling chamber; the hydraulic jack is horizontally distributed on the inner side of the propelling chamber; an ejection end of the hydraulic jack is fixedly connected with the inner side of the propelling chamber; the other end of the hydraulic jack is fixedly connected with a hydraulic jack connecting block; the lengthening rod comprises an upper lengthening rod and a lower lengthening rod; one end of the upper lengthening rod is fixedly connected with the top surface f the hydraulic jack connecting block; the other end of the upper lengthening rod is connected with the end part of a drill rod of a drilling machine; and one end of the lower lengthening rod is fixedly connected with the bottom surface of the hydraulic jack connecting block. The invention also relates to the supporting-disk pouring pile with a plurality of supporting discs. The forming device of the supporting-disk pouring pile has a reasonable structure, is light in weight, is convenient to use, is high in construction speed and is wide in using range, and the thicknesses of the supporting discs prepared by using the device are uniform.