This paper analyzes the major network security issues existing in thermal power plants' control system of China

and lists the cases of domestic power plants attacked by malicious code and virus

as well as their hazards. On the basis of this

it proposes the methods for scientificly planning the optimal safety isolation region in the control zone I in power plants

reasonably deploying the internal network threat detection and audit platform of the thermal control system

and strengthening the inner network safety control of the control system and detailed implementation scheme. Finally

it emphasizes that ensuring network security needs to do a good job in network admission control of thermal control system in power plants and strengthening the training of information security technology for thermal control personnel.