The invention discloses a SVC controller for controlling voltage and a controlling method of the SVC controller. The controller comprises a signal input module, a low-pass filtering module, a judging module, a synthetic controlling module, a coordinating module and a signal output module. The signal input module, the low-pass filtering module, the judging module, the synthetic controlling module, the coordinating module and the signal output module are connected in sequence. The signal output module is respectively connected with the synthetic controlling module and the coordinating module. The SVC controller for controlling the voltage and the controlling method of the SVC controller have the advantages that when the problems of voltage stabilization occur in an electricity system, different controlling strategies can be adopted to conduct controlling according to different problems of the voltage stabilization, reactive power and voltage of the system are compensated through coordination of power and voltage, and therefore stability of the voltage is improved more reasonably.