The utility model belongs to the field of the power equipment monitoring, and specifically relates to a digital dielectric-loss measurement device using the time synchronization function of IEEE1588. The device mainly comprises a main industrial computer, a voltage acquisition unit, a current acquisition unit and a GPS clock server, and the IEEE1588 time synchronization protocol is used to enable a dielectric loss device to have a time synchronization function. By using the device, the accuracy and the reliability of the dielectric loss measurement are improved, and the intelligent transformation cost of electrical equipment is reduced; and the device has been effectively applied to a substation intelligent renovation project in Siping City in Jilin Province in the northeast.