The Smart Distribution Grid Monitoring System consists of SGS and SFPlatform. SGSs can be easily installed on overhead lines, underground cables and underground-to-overhead transit points. They are used to measure the line current, temperature and voltage with high precision and accurate timing synchronization. SFPlatform collects, records and analyzes the measuring data over time. Taking advantage of big data analysis, the system turns the collected raw data into the critical information as well as the visibility of distribution network, which helps utilities to reduce outage duration, increase transmission load and enables more and more distributed renewable energy to connect into grid.