The utility model provides a calibration system that puts into operation simulates in extra -high voltage transformer substation, include: voltage regulator, intermediate transformer, compensating capacitor group and the control unit, intermediate transformer is defeated by with the mains voltage pressure regulating to the voltage regulator, offer after the intermediate transformer vary voltage by the examination transformer, intermediate transformer is separate unit multi -gear output transformer, compensating capacitor group organizes through the reactive compensation contactor and articulates at intermediate transformer with on by the generating line between the examination transformer for carry out reactive compensation to the system, the control unit controls the action of reactive compensation contactor group so that compensating capacitor group drops into corresponding compensation capacitance according to intermediate transformer's parameter and the compensation capacitance who is dropped into by the parameter acquisition needs of examination transformer, the output of adjusting intermediate transformer according to the input voltage by examination transformer needs keeps off the position. Special high voltage transformers's once side power supply requirement can be satisfied, each item index experiment of high pressure, messenger's secondary side completion extra -high voltage is planned with low voltage and less current mode.