The iron and steel industry of China is suffering from overcapacity, safety risks, environmental pollution and other problems. Simultaneously, it faces common problems, such as data collection, remote control and real-time data interaction. The service framework of NFV and SDN are employed by 5G SA. There are three application scenarios, eMBB, uRLLC and mMTC, which are applied to social vertical industries. Core private network scheme based on 5G SA on is proposed in this paper, which realizes industry digital transformation through constructing digital smart applications. It will make the steel industry greener, more environmentally friendly and more energy efficient.