As one of the comprehensive economic indicators of the power industry, the line loss can directly reflect the rationality of the power grid structure and its operation mode, and also seriously affect the economic benefits of power enterprises. With the rapid development of intelligent power grid, there are higher requirements for the synchronous line loss of distribution network. This paper designs a synchronous line loss optimization system of 10 kV middle and low voltage distribution system, which consists of data acquisition unit, transmission unit and analysis unit.Among them, GPRS public network and 230M wireless special network serve as the channel for information transmission. Data analysis unit consists of data reading, topology analysis and line loss calculation. In view of the serious loss of data in the current electricity collection process, the large error and low reliability in the process of acquiring line loss in the same period, in the process of line loss calculation, this paper introduces a hierarchical node identification strategy, puts forward the load node intelligent identification method based on support vector machine (SVM), which can effectively, fastly calculate various load node injection current, reduce the line loss error caused by non-synchronous data. Finally, the feasibility and effectiveness of the system in line loss calculation are verified in practical case. This system could be used to intelligent distribution network planning and design, production and operations management to provide reliable basis.