In this paper, we proposed a parallel simulation method for performance analysis of the Global Navigation Satellite System (GNSS) based on simulation model portability 2(SMP2) and service-oriented modeling method. GNSS is a space engineering system with a large-scale and complex structure, and the proposed method can be used to construct large complex simulation systems to gain the reusability, composability and interoperability of heterogeneous simulation resources. Firstly, the method including the conceptual framework, system architecture and system engineering process is introduced. Then the parallel model development, composition and schedule method are detailed respectively. Finally, a distributed M&S environment based on service-oriented SMP2 is designed, and an example of navigation system volume simulation is given to validate the whole method.