Abstract: The present invention relates to a portable low-frequency electrotherapy apparatus comprising a main body which comprises a universal serial bus (USB) port, a charging part to receive a charging voltage from the power pin of the USB port and a low-frequency signal generator electrically connected to a data pin of the USB port to supply a low-frequency signal through the data pin of the USB port; a low-frequency signal cable which comprises a low-frequency electrode connector at one end of the low-frequency signal cable electrically connected to the data pin of the USB port and an electrode pad at the other end to transmit a low-frequency signal to a human body; and a power cable which comprises a power supply connector at one end of the power cable electrically connected to the power pin of the USB port.