With the increasing short-circuit power of system,it is an effective way to solve the large capacity of short-circuit breaking by using parallel breaking technology which composed by a high coupling splitter reactor and two parallel breakers in series.According to research the TRV equivalent calculation circuit and initial conditions in equal current mode and limit current mode respectively,the prospective TRV of CB1 and CB2 have been calculated for rated voltage of 252 kV and rated short-circuit current of 85 kA.The results indicate that TRV of CB1 and CB2 are not affected by high split coupled reactor in equal current interruption mode,and TRV of CB1 is under the standard requirement values after first current zero crossing and the TRV of CB2 is exceed the standard requirement values after second current zero crossing which is also higher than the ITRV and line-side TRV of SLF in limit current interruption mode.Furthermore,the research conclusions of this paper can provide the theory and reference basis for parallel breaking technology.