This paper mainly deals with the distribution automation based on IEC 61850. First the IEC61850 protocol is analysed, and relevant units such as distribution automation structure is shown. The switch, RTU, master unit, communication network are illustrated. Then the major functions of distribution automation system are demonstrated, including fault location, voltage control and distribution network reconfiguration. The time synchronization and network redundancy are also analysed. Next, the important units in distribution automation are modelled, including MU IED, P&C IED、PMU IED、circuit breaker IED as well as communication network traffic. In the end, the future works are proposed.