Abstract: Ion thruster has become the first choice of the propulsion system for the future space exploration missions for its high specific impulse, long lifetime and continuous thrust adjustment. Optimization of the ion thruster is usually realized by large numbers of experimental tests. Current simulation models developed only focus on the components themselves and ignore the interactions between components. The professionally numerical model that takes these interactions relationship into account should be developed. However, the complicated structures and coupled interactions between plasma, electric potential, magnetic field, particle collisions, particles and walls, it isimpossible to simulate the working processes simultaneously. A similar coupling simulation method is proposed, where the component itself is treated as a whole but it is simulated by giving the coupling interaction as the boundary conditions. Coupling simulation models of two components are established independently and their interactions are simulated. The results show that the plasma micro-parameter changes tremendously when it works alone or not.