Abstract: In recent years, the load level of Pudong Power Grid is increasing year by year. In the summer peak period, the allowable capacity of the distribution line is the bottleneck of the power distribution network. In order to improve the power supply capacity of the existing heavy load distribution lines and the utilization efficiency of the line equipment assets, a dynamic line rating system, this can be applied to the insulated conductors and bare wires of the distribution lines. The system is designed and applied to the 35kV and 10kV overhead distribution lines in the Pudong power grid. Through the operation of last year's summer peak, the system can increase the capacity of the distribution line by about 20%. It can provide a scientific reference for the dispatching and inspection personnel to take the instantaneous safety measures at the peak time of the power consumption, and reduce and even eliminate the unnecessary load reduction operation in some cases.