A power module, characterized in that the power module comprises a first EMI, Electromagnetic Interference, module, a second EMI module, a rectifier module, a PFC, power factor correction, module, a selecting module, and a DC/DC, Direct Current/ Direct Current, module; wherein the first EMI module is configured to connect an output of a parallel connection of a group battery and an AC/DC module which is configured to convert an input first alternating current into a first high voltage direct current; wherein the battery group is configured to output a standby high voltage direct current when the first high voltage direct current is abnormal, and the output of the parallel connection is a third high voltage direct current; the first EMI module is further configured to filter the third high voltage direct current, and output the filtered third high voltage direct current to the selecting module; the second EMI module is configured to receive a second alternating current; wherein the second alternating current is configured to pass through the second EMI module, the rectifier module, and the PFC module to output a second high voltage direct current; wherein, the power supply branch of the second alternating current does not require power backup, the power supply branch of the third high voltage direct current is configured to use the battery group for power backup; the selecting module is connected to channels for inputting two high voltage direct currents to the DC/DC module, wherein the two high voltage direct currents comprise the second high voltage direct current and the filtered third high voltage direct current; the selecting module is configured to: when it is detected that the second high voltage direct current is normal, connect a channel for inputting the second high voltage direct current to the DC/DC module and disconnect a channel for inputting the filtered third high voltage direct current to the DC/DC module; when it is detected that the second high voltage direct current is abnormal, connect the channel for inputting the filtered third high voltage direct current to the DC/DC module and disconnect the channel for inputting the second high voltage direct current to the DC/DC module; and the DC/DC module is configured to convert the input second high voltage direct current or the filtered third high voltage direct current into a low voltage direct current, and output the low voltage direct current to a load for use. the first EMI module is configured to connect an output of a parallel connection of a group battery and an AC/DC module which is configured to convert an input first alternating current into a first high voltage direct current; wherein the battery group is configured to output a standby high voltage direct current when the first high voltage direct current is abnormal, and the output of the parallel connection is a third high voltage direct current; the first EMI module is further configured to filter the third high voltage direct current, and output the filtered third high voltage direct current to the selecting module; the second EMI module is configured to receive a second alternating current; wherein the second alternating current is configured to pass through the second EMI module, the rectifier module, and the PFC module to output a second high voltage direct current; wherein, the power supply branch of the second alternating current does not require power backup, the power supply branch of the third high voltage direct current is configured to use the battery group for power backup; the selecting module is connected to channels for inputting two high voltage direct currents to the DC/DC module, wherein the two high voltage direct currents comprise the second high voltage direct current and the filtered third high voltage direct current; the selecting module is configured to: when it is detected that the second high voltage direct current is normal, connect a channel for inputting the second high voltage direct current to the DC/DC module and disconnect a channel for inputting the filtered third high voltage direct current to the DC/DC module; when it is detected that the second high voltage direct current is abnormal, connect the channel for inputting the filtered third high voltage direct current to the DC/DC module and disconnect the channel for inputting the second high voltage direct current to the DC/DC module; and the DC/DC module is configured to convert the input second high voltage direct current or the filtered third high voltage direct current into a low voltage direct current, and output the low voltage direct current to a load for use.