Classified the power supply region based on the requirment of power supply reliability in progress of distribution automation designing. According to different feeder types and modes of connection,combined with the construction principles of distribution automation system,proposed a specific configuration method to the number and the function of distribution terminal units,found influcing factors in the configuration process at the same time.Contraposed the urban distribution network located in Shangrao City,Jiangxi Province to do some instance analysis,validated the practicability and the feasibility of the method we proposed.