Variable-diameter reinforcing cage for anchor rod or pile foundation

A variable-diameter reinforcing cage for an anchor rod or pile foundation, comprising an axial rod, a plurality of vertical bars, at least two circular fixators and several groups of ribs which correspond to the circular fixators. The circular fixators are all sleeved on the axial rod; one end of the ribs is movably connected to the position of the vertical bars at the same height, and the other end of the ribs is movably connected to the circular fixators; annular hoops are arranged on the periphery of the vertical bars to serve as circles of latitude; fixing points are formed on the annular hoops and the vertical bars; and the annular hoops are annular spiral spring hoops of an elastic material or flexible steel wires.