The invention discloses an assembled working platform for high pier construction. Pre-embedding steel plates are fixed to the upper and lower parts of the side surface of a pier column. Locks are arranged on the pre-embedding steel plates on the upper and lower parts. The two locks jointly fix a vertical rod. The upper part of the vertical rod is fixed to the pier column through a climbing awl. Anupper ear plate and a lower ear plate are respectively fixed to the upper and lower parts of the vertical rod. A horizontal load-bearing rod with a transverse sliding groove is arranged. One end of the horizontal load-bearing rod is movably connected to the upper ear plate. A sliding diagonal brace is arranged. One end of the sliding diagonal brace is movably connected to the lower ear plate, theother end is mounted in the sliding groove, and the sliding diagonal brace can move along the sliding groove and is fixed to the sliding groove. A foot pedal is arranged on the horizontal load-bearing rod. The assembled working platform for high pier construction has the advantages of simple structure, light weight of single-piece structure body and safe and reliable aloft work. In a process of dismounting, a sliding lock temporary anchoring device is used for overall dismounting, which is convenient and reliable.