1000 kV UHV Nanyang substation is a UHV AC demonstration substation engineering project in our country.The UHV transformer is an important equipment in the substation.There are two transformers,which were produced by different companies,using fully compensated and non-fully compensated regulation-compensation principle.The winding connection method and regulation-compensation principle of the two transformers are introduced.The Simulink simulation models of the two transformers are established.The simulation data of the voltage of the transformer confirms the correctness of the simulation model.Finally,some suggestions on the construction of UHV are put forward according to the comparison results,which provide reference for the construction of UHV at later stage.