A power supply device , comprising a primary conversion circuit , a secondary conversion circuit , and a transformer between the primary conversion circuit and the secondary conversion circuit , wherein the primary conversion circuit is configured to perform primary rectification and/or primary filtering on input alternating current, the transformer is configured to couple an output power of the primary conversion circuit to the secondary conversion circuit , the secondary conversion circuit is configured to perform secondary rectification and secondary filtering based on a power coupled from the primary conversion circuit to the secondary conversion circuit to generate an output current of the power supply device , and the secondary conversion circuit comprises an inductance element (L) for secondary filtering, the power supply device further comprises: a feedback control circuit , wherein an input end of the feedback control circuit is coupled to both ends of the inductance element, and the feedback control circuit is configured to sample the output current of the power supply device based on an impedance of the inductance element to obtain a current sampling value of the output current of the power supply device , and to generate a feedback signal according to the current sampling value, wherein the feedback control circuit includes a galvanometer and an operational amplifier, wherein the galvanometer is configured to sample the current across both ends of the inductance element to obtain the current sampling value, and to convert the current sampling value to a corresponding voltage sampling value, wherein the operational amplifier is configured to compare the voltage sampling value with a reference voltage value, to generate the feedback signal; the power supply device further comprising: a power adjustment circuit , coupled to an output end of the feedback control circuit , and configured to adjust the power coupled from the primary conversion circuit to the secondary conversion circuit via the transformer according to the feedback signal. the power supply device further comprises: a feedback control circuit , wherein an input end of the feedback control circuit is coupled to both ends of the inductance element, and the feedback control circuit is configured to sample the output current of the power supply device based on an impedance of the inductance element to obtain a current sampling value of the output current of the power supply device , and to generate a feedback signal according to the current sampling value, wherein the feedback control circuit includes a galvanometer and an operational amplifier, wherein the galvanometer is configured to sample the current across both ends of the inductance element to obtain the current sampling value, and to convert the current sampling value to a corresponding voltage sampling value, wherein the operational amplifier is configured to compare the voltage sampling value with a reference voltage value, to generate the feedback signal; the power supply device further comprising: a power adjustment circuit , coupled to an output end of the feedback control circuit , and configured to adjust the power coupled from the primary conversion circuit to the secondary conversion circuit via the transformer according to the feedback signal. <EOS>