Abstract: As the large-scale new energy is connected into the grid, the electromagnetic transient characteristics of traditional power grid have been greatly changed owing to the access of the massive power electronic components. Therefore, new requirements of the power grid simulation have been put forward from both the algorithm and the calculation scale. The electromagnetic transient model of Inner Mongolia power grid with new energy access is built based on PSCAD software to realize the accurate simulation of the electromagnetic transient of the whole network. Based on cluster parallel simulation technology, the problem that the computing scale is too large to be computed or the simulation efficiency is low is solved. Furthermore, a network equalization integration method based on the size of the node matrix is proposed, which reduces the occupancy rate of computing resources. The simulation results show that the cluster parallel technology can effectively improve the simulation efficiency of the new energy grid-connected electromagnetic transient model. At the same time, under the premise of ensuring the simulation speed, the proposed network equalization integration method can optimize the utilization efficiency of computing resources.