The high-precision time synchronization of each node in the power distribution field network is an important technical support for realizing real-time and refined business. For the power distribution field network based on high-speed power line broadband carrier communication,a step-by-step precision time synchronization strategy is designed. Firstly,the clock of the central node is calibrated in real-time by the communication master station through the long-distance communication network and used as the master clock of the field network. Secondly,relying on the low latency,the broadcast mechanism,and the network time base of the field network,the time and frequency of the clocks of each node in the network are accurately monitored and their deviations are obtained. Thirdly,the clock frequency is adjusted by re-calibrating the temperature compensation coefficient of the node clock,so that the node time is gradually synchronized within a timing cycle. Finally,the time synchronization performances of the field network are tested in the laboratory and job site. The test results show that the time synchronization accuracy of the field network is within ±0.23 s during a day,which is 28% higher than that of the power distribution field network based on narrowband power line carrier,and these phenomena of time gap or time repetition are avoided in the time synchronization process.