The present invention provides a supporting pole. The supporting pole includes a metal inner pipe having an upper end and a lower end, with a reserved pipe portion on at least one of the upper end and the lower end. The supporting pole further includes an outer wrap layer wrapping the metal inner pipe except the reserved pipe portion, and a cone-shaped sleeve covering the reserved pipe portion. The reserved pipe portion has a plurality of axial grooves formed by a clamping and closing process that invigilates a wall of the reserved pipe portion, such that the reserved pipe portion has alternating protrusions and grooves. A maximum outer diameter of an open end of the reserved pipe portion is less than an outer diameter of the metal inner pipe. The cone-shaped sleeve is produced by injection molding.