5G co-construction and sharing has been successfully carried out in China, and has become a key measure to improve the quality and reduce the cost of 5G mobile network. The demand of traditional voice service is the basic service of 5G network construction. In this paper, the voice service solutions under different 5G networking modes are discussed, and the VoLTE voice service capability under the shared networking mode of 5G NSA access network is deeply studied. Two technical solutions are proposed for VoLTE being carried in the 4G shared anchor cell of the contractor or in the home 4G cell. Two schemes are analyzed and compared. The 4G anchor point establishment and release process, service mobility, etc. are tested in the field, and the test results are given.