Since the interactivity, integrality and instantaneity of the data communication in smart substation have been improved to a higher degree, it can contribute to the construction and realization of substation area backup protection (SABP). In this paper, the structure and characteristics of smart substation were introduced firstly, and the application concept about SABP was presented in detail. According to the comprehensive treatment and judgment for the digital information of whole substation, such as voltage/current samplings of multiple bays, status of circuit breakers, etc., this type protection system can implement the backup protection function for each electrical element inside smart substation. In addition, with regard to the protection algorithm and application structure of SABP, as well as the coordination relationship between SABP and main protection, a few correlation analysis and discussions were carried out. From the analysis results, it can be considered that, the construction of SABP can effectively promote a substation area range of data information sharing and help to enhance the whole protection system's operation performance.