Abstract: In the multipactor investigation of dielectric window, the effect of low energy electron is usually neglected. In this paper, a homemade Monte Carlo model was developed to simulate the multipactor mechanism of the RF window. By comparing the multipactor susceptibility curves obtained under the classical Vaughan secondary electron emission model and two modified Vaughan models (fitted by Rice and Vincent respectively), the influence of low-energy electrons on the multipactor effect of the dielectric window was obtained. The simulation results demonstrate that under effect of the tangential electric field, the susceptibility curves obtained by the three emission models almost overlap. Low-energy electrons have little effect on the susceptibility curves, and the Rice model has the largest discharge region. In comparison, under effect of the normal electric field, the susceptibility area fitted by the Vincent model is much larger than the other two models. These characteristics should be taken into account in the research on the breakdown phenomenon of high-power dielectric window and breakdown suppression technology.