A copper wire interface circuit is provided, where a current output amplifier is connected to a port impedance component and a transmit end, and the current output amplifier is configured to amplify a to-be-transmitted signal; the port impedance component is connected to a high-pass filter, impedance, after undergoing impedance transformation performed by the high-pass filter, of the port impedance component is used for performing impedance matching with equivalent impedance of a cable and a load; the high-pass filter is connected to the port impedance component and the cable, the high-pass filter is configured to filter the to-be-transmitted signal or a received signal and perform impedance transformation on the port impedance component; and an echo cancellation module is connected to the port impedance component and a receive end.