Abstract: Due to the high concealment of virus intrusion outside the network and many types of intrusion, it is difficult for the virus to be fully sensed, which leads to a threat to the operation security of the power grid dispatching automation system. In order to improve the network security of power grid dispatching automation system, a network security situational awareness technology of power grid dispatching automation system based on random matrix theory（RMT） is proposed. The network security information data of the power grid dispatching automation system is collected, the security state distribution model under the virus invasion environment is constructed, and the extraction of the network security situation characteristic information of the power grid dispatching system is completed through using the model. The M-P law and the single-loop law in RMT are used to analyze the distribution of the eigenvalues of the network security situation in the random matrix to realize the network security situational awareness of power grid dispatching system. The experimental results show that by carrying out the security situational awareness test of the method, it is verified that the proposed method is applied to the power grid dispatching system with high accuracy of component security situational awareness and network security situational awareness, which reflects the effectiveness of the method.