The invention discloses an optimization configuration method of position of a power electronic transformer direct-current port current transformer. The method comprises the following steps: 1, obtaining specific parameters of power electronic transformer equipment and circuits; 2, calculating the resonance current of a discharge loop by utilizing the specific parameters of the equipment and the circuits; and 3, comparing the resonance current peak values of the discharge loop, and determining the position of the power electronic transformer direct-current port current transformer. According tothe invention, by analyzing the current oscillation and current waveforms of the direct current side of the power electronic transformer, a direct-current side sensor installation position optimization selection method is given, so direct-current circuit current protection caused by response oscillation current at the moment when a direct-current circuit switch is closed can be effectively avoided, and normal and reliable grid-connected work of a direct-current port of a power electronic transformer is guaranteed.