Abstract: Multisampling is a potential way to enhance control performance of low-switching frequency converters. However, based on the traditional multisampling model, the analysis error of high-frequency characteristics is large, making it difficult to accurately predict high-frequency resonance caused by perturbation sidebands. Therefore, high-frequency modeling of multi-sampled converters needs further exploration. This article analyzes the description function of multisampling pulse-width modulation (PWM) when perturbation under fundamental modulation signal is injected, so as to build a multi-frequency model of multisampling PWM. Based on this model, a multifrequency admittance model of multisampling converters is proposed. Compared with the traditional one, it can accurately describe the high-frequency admittance characteristics, and the sweep frequency results also verify the correctness of the proposed model. Then, stability analysis is carried out under the proposed model, which can accurately predict high-frequency resonances that traditional models cannot predict. And in terms of the high-frequency instability caused by perturbation sidebands, a resonance suppression strategy is given to ensure the high-frequency stability. Finally, the experimental results verify the effectiveness of the theoretical analysis in this paper.