A power transformer is a static electrical device that is used to convert a certain value of AC voltage (current) into another or several different values of voltage (current) with the same frequency. When alternating current is supplied to the primary winding, alternating magnetic flux is generated. The alternating magnetic flux induces AC electromotive force in the secondary winding through the magnetic conduction of the iron core. The level of the secondary induced electromotive force is related to the number of turns of the primary and secondary windings, that is, the voltage is proportional to the number of turns. The main function is to transmit electrical energy, therefore, the rated capacity is its main parameter. Rated capacity is a common value that expresses power. It represents the size of transmitted electric energy, expressed in kVA or MVA. When the rated voltage is applied to the transformer, it is used to determine the rated current that does not exceed the temperature rise limit under specified conditions. The more energy-saving power transformer is the amorphous alloy core distribution transformer. Its biggest advantage is that the no-load loss value is extremely low. Whether the no-load loss value can ultimately be ensured is the core issue to be considered in the entire design process. When arranging the product structure, in addition to considering that the amorphous alloy core itself is not affected by external forces, the characteristic parameters of the amorphous alloy must be accurately and reasonably selected during calculations.