According to the characteristics and the existed potential safety hazard of the smart substation measuring system, this paper has explored the smart substation measuring system security protection technology from data encryption, designing of security authentication and key agreement protocol, access control and etc. Above technology has been used in smart substation measuring system and has been verified, the verify results show that the smart substation measuring system security protection technology can effectively against such attacks as viruses, DDos, replay and so on, effectively realize the identity authentication and key agreement, effective block the unauthorized device to access to the system at the premise condition of not affect the transmission data’s real-time performance and reliability. So, it has high popularization and application value.