The invention relates to a PMU synchronized clock system added by dynamic compensation belonging to the electric power system monitoring and controlling technology field, which comprises a GPS module,a crystal oscillator clock module, a microprocessor and a dynamic error processing system. Wherein, the GPS module sends the outputted data frame to the microprocessor, and sends second pulse signalto the dynamic error processing system; the crystal oscillator clock module sends the outputted second pulse signal to the dynamic error processing system; the dynamic error processing system performsjudging and error processing to the second pulse signals; the microprocessor receives the RS-232 data frame from the GPS module, processes the serial outputted time message in real time and sends itto the PMU sampling system, receives the signal from the dynamic error processing system at the same time, and adjusting the signal correspondingly. The invention improves the clock precision, and canwork normally and guarantee the phase angle measuring measurement error in the predetermined range even under the satellite losing lock or satellite experiment jumping condition, thereby, guaranteesthe system reliability.