In this paper, a digital twin (DT) system of the chaotic torsion pendulum based on reservoir computing (RC) is developed.By calculating the reconstruction similarity of phase portrait δR and the prediction length of trajectory LP, the capability of the digital copy of this DT system to accurately capture and generate the current and future dynamic states of the experimental device is verified. The DT system developed in this work provides students with an effective auxiliary tool for the chaotic pendulum experiment in collegelevel physics.