Microgrids have strong flexibility, reliability, and controllability. The application of microgrids to secure power networks can enhance the safety of power supply, the ability to resist disasters and quickly restore power in the urban cores. However, because of the different components and operating objectives, the existing planning methods cannot be applied to secure power networks with microgrids. Therefore, a planning method for secure power networks with microgrids based on survivability evaluation is proposed in this paper. The impacts of microgrids on the operation of the secure power networks are considered, and the importance indices of branches and nodes of the distribution network are proposed. A survivability index system for a secure power network with microgrids considering resistance, safety, and recovery is constructed, and the search model for secure power networks with microgrids is established. The examples show that the continuous power supply of important loads under severe natural disasters, and the safe operation as well as the ability of fast-recovered power of the secure power network can be ensured with this method. This work is supported by National Natural Science Foundation of China (No. 51877018).