With the rapid development of Synchronous Digital Hierarchy (SDH) technology, it has been more and more widely used in power communication networks. The power communication network has high requirements on the reliability of data transmission, and the self-healing ring has the advantages of automatic fault recovery, high reliability, flexible networking, and simple implementation, thus becoming an indispensable part of the construction of power communication SDH networks. How to effectively evaluate the self-healing ability of SDH and improve the performance of the transmitted services has become an urgent problem to be solved. In the actual operation of the network, the selfhealing capability of SDH cannot be accurately and effectively evaluated. Therefore, on the Exata simulation platform, the SDH transmission network equipment, network, services and other resources and self-healing behavior are modeled to achieve the SDH. Transmission network "fault occurrence-fault detection-fault recovery" this self-healing process simulation. Finally, a comparative evaluation of the availability of access networks and backbone networks was carried out for a protection network in a certain area, verifying that the channel protection function of SDH self-healing rings can effectively improve the security and reliability of the power grid.