A reconfigurable PUF device based on fully electric field-controlled domain wall motion includes a voltage control layer, upper electrodes, a lower electrode, antiferromagnetic pinning layers, and a magnetic tunnel junction (MTJ). The MTJ includes, from bottom to top, a ferromagnetic reference layer, a potential barrier tunneling layer and a ferromagnetic free layer. In the device, an energy potential well is formed in a middle portion of the ferromagnetic free layer by applying a voltage to the voltage control layer to control magnetic anisotropy, and a current is fed into either of the upper electrodes to drive generation of the magnetic domain walls and pin the magnetic domain walls to the potential well. After the voltage is removed, the potential well is lowered so that the magnetic domain walls are in a metastable state, thereby either a high resistance state or a low resistance state is randomly obtained.