A universal control strategy is proposed in this paper to improve the performances of electric springs(ESs) based on current-source inverters(CSIs). The proposed control can realize the functions of voltage regulation, harmonic suppression, and power factor correction(PFC) at the same time. The single-phase topology of ES with CSI is described firstly, and its operating principles are analyzed by means of phasor diagram and current decomposition. Then the proposed control strategy is analyzed in detail. In the proposed control, a cascade generalized integrator (CGI) is used to construct the quadrature signal generator(QSG), in order to enhance the capability of harmonic compensation and PFC of ES. In addition, a dq0 transform module is used to decouple the active power and reactive power of ES. Finally, the effectiveness and feasibility of the proposed control is verified by simulation and experimental results in the case of normal voltage, over-voltage, and under-voltage, respectively.