Abstract: 5G private network is a dedicated private network that provides services for vertical industries such as military, manufacturing, and medical applications. It is mainly used to maintain high-reliability, low-latency, and high-security connections under the limited 5G public network, in order to prevent loss of economic security caused by misoperation of command and control in special industries. For the deployment plan of 5G private network, the security requirements are analyzed, the targeted security technology is investigated, and the future direction of 5G private networks security that needs further research is discussed.