System-level diagnosis was introduced into the fault diagnosis for satellite networks.A novel modeling method for satellite networks

two-level-node graph

was presented to characterize the specialty that a satellite could have more than one communication directions and its communication function could be faulty partly.Then a strategy of the system-level fault diagnosis for satellite networks was designed based on broadcast and its communication complexity was analyzed theoretically.The satellites' broadcast and one to many communication modes were taken advantage of when testing so that our strategy is applicable to arbitrary topology and saves communication overhead.Simulation results show that the communication overhead reduces while the number of ports

which can communicate

decreases.