Abstract: In order to avoid drawing a large reactive power from the alternating current line, the White circuit type resonant network is adopted widely as the structure of the magnet power supply system of the rapid-cycling synchrotron. Reducing the total harmonic distortion （THD）of the magnet current in the parallel resonant network is the key technique for the magnet current tracking accuracy. Based on the dynamic response analysis of a single mesh parallel resonant circuit in the paper, it shows that the continuous power excitation is of great benefit to reducing the magnet current harmonics. The paper also gives a description of our experimental studies on the dynamic response with the pulse and continuous power excitation in a parallel resonant network model.