<p>With the widespread use of pulse loads in islanded DC microgrids, the stability issues induced by pulse loads have received increasing attention. However, the periodically time-varying characteristics of pulse loads make the stability analysis and control of DC microgrids containing pulse loads particularly challenging. To address this problem, this paper develops a new method to evaluate the voltage oscillation induced by the pulse load and proposes a corresponding oscillation suppression technique to enhance system stability. First, a harmonic state space–based impedance model is proposed to characterize the periodically time-varying nature of pulse loads. Based on the developed impedance model, a stability criterion and a voltage oscillation evaluation method are proposed. Moreover, an impedance notch strategy is proposed for the energy storage converter to suppress the voltage oscillations induced by pulse loads. The effectiveness and advantage of the proposed method are validated by case studies including comparative study and hardware-in-loop experiments.</p>