Because of the complexity of the communication equipment spare part support system, the use of technique of modeling and simulation is applicable and effective in the study of the system performance. Aimed at the scheme of spare part under two-grade support system, based on the analysis of flow for communication equipment spare part support system and regarding the spare part utilization and restoring rate as indexes, the flow simulation model of spare part support system is built by Arena. The law affecting the spare part utilization rate and restoring rate under two-grade maintenance support by the connection spare part configuration policy is analyzed through example simulation, which verifies the effectiveness of the model. Simultaneously, in the course of analyzing and describing the stochastic characteristics of variable and the dynamic process of the system, Arena is more effective and superior than the traditional modeling methods.