To solve the problem of identity authentication in microgrid system, a microgrid security login system based on SM2 smart card is designed. Firstly, with SM2 smart card as the core, the process of user identity au- thentication is described. Then the security of the scheme is analyzed. The scheme is characterized by anti-counterfeiting, anti-tampering and anti-replay. Finally, the system is implemented on the embedded development platform. The experimental results show that the system has a certain stability and efficiency, which has certain significance for the safe and stable operation of microgrid system.