Aimed at the characteristics and the security requirements of 10kV Power network distribution automation system, a set of security mechanisms is designed, which is based on Elliptic Curves Cryptography. The identity authentication between sub-station and distribution terminal unit is actualized by using ECC signature algorithm. Data integrity is actualized by Hash function and data encryption is actualized by ECC encryption schemes. We develop a GUI (Graphical User Interface) as the simulation platform by using java language.