Abstract: In this study, a novel arcless on-load tap-changing model is proposed, it adopts inverse paralleled high-power thyristor pair to be control switch and regulate the output voltage by switching in corresponding tap-changing windings and also use thyristor�s zero-current cut-off character to cancel transition resistance inserting process to simplify the regulation steps effectively. A 35kV/10.5kV��5000kVA two�winding transformer model is built by MATLAB and the simulation wave form of tap-changing process has proved that this model is correct.