Given that the analysis and computation of large scale power system are time-consuming， a multi-core parallel computation technique suitable for power system analysis is proposed. Taken the example of short-circuit fault analysis， a detailed procedure is provided on how to apply the multi-core parallel computation to decompose and solve the node based matrix. The method proposed is verified by the simulation tests and the comparative analysis on the results with or without using this method. Furthermore， a test on the fault computation on the Central China power grid is conducted and the performance of multi-core parallel computation and of clustering computation is compared. The results show that the method proposed is correct and effective.