The influence of the dinitrogen tetroxide （N₂O₄） content， temperature and pressure on the diffusion and adsorption behavior of N₂O₄ in fluoroether rubber was investigated by employing the full atomic molecular dynamics simulation and grand canonical Monte Carlo simulation. The results show that the free volume of the system increases with the N₂O₄ content， which enhances their diffusion coefficient. In addition， the free volume of the system becomes smaller with increasing the external pressure which reduces the diffusion coefficient. Furthermore， the high temperature increases not only the free volume but also the velocity of atoms. As a result， the diffusion coefficient of N₂O₄ is increased which exhibits an Arrhenius-like behavior. Moreover， the solubility coefficient of N₂O₄ in fluoroether rubber decreases rapidly with the increase of temperature. Therefore， the permeability coefficient of N₂O₄ in fluoroether rubber first increases slightly and then decreases with the increase of temperature.