The invention relates to a delayed time processing and compensating system for wide-area damper control of an electric power system and belongs to the stability and control technical field of the electric power system; the delayed time processing and compensating system is characterized in that: the system is composed of a controlled electric power system, a feedback signal time delay circuit of the electric power system, a band-pass filter, a dephasing compensator, a time delay free wide-area damping controller and a control output signal time delay circuit which are sequentially connected in series in a closed loop way; wherein, the setting wide-area damper controlling target is that a pole point which is corresponding to the low damping low-frequency oscillation mode on a complex planeis shifted left to the condition that lambda0 is equal to sigma0 + jomega0, and then according to actually measured frequency response of the electric power system, a phaseshift link circuit is used for counteracting retarding phase produced at the low-frequency oscillation point owning to time delay of a control circuit, and the phase margin of the system is improved by the band-pass filter for making up the lost phase margin caused by phaseshift owning to time delay, thus preventing the system from losing stability. The system leads the wide-area damping controller to still keep the system stability when the size of the total time delay of the control circuit is 0ms-600ms, and the damping effect is the same as the effect without time delay.