To the challenge relay protection faced during the process of smart substation development, State Grid Corporation of China has set a series of standards to lead its fast and normal development. This paper classifies and interprets relative technical specifications from the perspective of integrated design, engineering management and on-site working, revealing the background and usage of them. Besides, two application instances, which are remote control and reconstruction project of substation bay, are taken as examples to demonstrate the practical use of these technical specifications. Finally, some existing problems are summarized and the development direction are explored in the view of setting and perfecting technical specifications.