With the continuous development of telecommunications industry, building a voice core network structure and achieving a safe and stable operation environment are the important parts of the development of telecom industry in the new era. At present,Telecom Group is striving to build efficient network operation capability, and the effective maintenance of voice core network is the key to improve the safety and stability of network operation. From the two aspects of voice problem and network security problem,this paper analyzes the problems and their causes. On this basis, it expounds the maintenance and management measures of the voice core network, to ensure the safety and stability of the network.