The performance of microchannel plate (MCP) detectors, including the temporal and spatial resolutions, varies significantly for MCPs work in a saturated mode due to high intensity illumination. In this paper, the influence of positive charges which accumulate on inner channel wall was added to a electron cloud motion model. It is the main difference between the MCP model in a saturated and a non-saturated mode. The kinetic characteristics of the electron clouds were calculated and analyzed. Simulation results show that the Energy Distributions Of Electrons (EDOEs), in a saturated mode, have a similar shape for MCPs with different electrode penetrate depth. This is very different from the results obtained in a non-saturated case. It is concluded that these phenomena come from the accumulation of positive charges near the exit of the channel. The EDOEs fit well with the experimental data of related literature, which verifies the correctness of this model.