This study investigates the technology related to the network isolation. As depicted in the history and practice of network isolation technology through the concept of network isolation, thereby search for the technical principle of Physical Isolation Netgap. To collect the management control measures related to network access through the practice norm of ISO27002 Information Security Standard. In order to compare with the control measures between different network isolation technology. The result is displayed that the Fifth Generation Network Isolation Netgap can manage both physical network isolation and efficient secure data exchange, it’s a great solution for managing network efficiency and security management. The research is also presented the technical specifications for the network isolation products according to the viewpoint of the Fifth Generation Network Isolation technology. The conclusion shows that the government should take the responsibility to support the relevant industries if we want to compete with other countries in the domain of network defense technology. To develop our own network isolation technology and products for enhancing the protection ability in confidential and sensitive information.