Abstract: To solve the problem of the vacuum plume effect caused by the spacecraft thrusters, the optimal layout design of the thrusters is made based on the vacuum plume effect analysis. The heat fluxes on the surfaces of the spacecraft are obtained for different layouts of the thrusters. By increasing the thrust line angle and the altitude of the fix point of the thruster, the core region of the plume will disappear from the surface of the spacecraft, and the heat flux on the surface of the spacecraft will be decreased. This method could help the layout design of the thrusters, with consideration of the thrust loss, the layout envelope and the bracket design of the thrusters, and two schemes of thermal protection of plume are put forward, for the layout design of spacecraft thrusters.