The discharge disturbance of Hall thruster has been exerted a significant impact on the on-orbit operational reliability in the propulsion system. In order to clarify the triggering mechanism of the discharge disturbance, the present study proposes a two-dimensional numerical model for the wall exfoliation transportation in Hall electric propulsion. Specifically, besides the transport process simulation of plasma, the numerical simulation of the microscopic process of the disturbance triggered by the exfoliation is achieved by simulating the process of charge absorption, transport, and collision of the exfoliation in the plasma flow field, combined with the feedback regulation model of the power supply. The calculation results showed that the detachment and transport of the exfoliation can triggered the current fluctuation simultaneously, and the electron density distribution and anode current fluctuation data at several typical moments could be used to compare the evolution of the two kinds of discharge disturbances. On this basis, to verify the correctness of the mechanism research, a discharge disturbance monitoring test of Hall thruster in a vacuum chamber was conducted. Current and image data during the discharge disturbance process were collected using an oscilloscope and a high-speed camera. It was found from the test that the discharge disturbance was synchronous with the detachment and transport of the exfoliation, and the different discharge disturbance forms were caused by the different movement direction of the exfoliation to the upstream/downstream. The main conclusions are as follows: Hall propulsion has two forms of discharge disturbance. One is the plummeting current-carrying type disturbance caused by the downstream movement of the exfoliation (already published in the literature), and the other is the soaring current-carrying type disturbance caused by the upstream movement of the exfoliation (not published in the literature). Moreover, the formation of discharge disturbance is directly related to the attenuation of the ionization by the exfoliation and the charge deposition of the exfoliation onto the anode. This study provides a theoretical basis for the establishment of methods to suppress discharge disturbance.