Abstract：Based on the theoretical analysis for the loss factors of the power transfoI1Tler，the measures of manufac— turing materials，core structure and manufacturing techniques were proposed to reduce the energy loss．The energy saving methods，such as the economic~running and voltage adjusting methods were put forward．At last the energy eficiency standards at home and abroad for the transformer running were introduced，which was useful for the ener— gY saving running and the application of the power transform er．