In the recent years, multi-core processors prove their extensive use in the area of System-on-Chip (SoC) on a single chip. This paper proposes a methodology and implements a multi-core simulator. The multi-core simulator is based on SimpleScalar integrated with SystemC framework, which deals with communication and synchronization among different processing modules. A shared memory scheme is introduced for inter-core communication with a set of shared memory access instructions and communicationmethods. A synchronization mechanism, which only switches the simulation component when communication occurs, is proposed for efficiency. Experiments prove that our simulator can correctly simulate the behavior of a multi-core system and demonstrate a high performance on Linux PC platforms.