The invention relates to the field of electric power telecommunication used for supporting smart power grids, in particular to a digital front end system used for power line carrier communication and an implementation method of the digital front end system. The digital front end system comprises a transmitter and a receiver, wherein the transmitter and the receiver carry out communication in sequence. The transmitter comprises an inversion Fourier transformation module, a windowing module I, an interpolation filter, a frequency mixer I and a digital-analog converter, wherein the inversion Fourier transformation module, the windowing module I, the interpolation filter, the frequency mixer I and the digital-analog converter carry out communication in sequence. The receiver comprises an analog-digital converter, a frequency mixer II, an interpolation filter, a windowing module II and a Fourier transformation module, wherein the analog-digital converter, the frequency mixer II, the interpolation filter, the windowing module II and the Fourier transformation module carry out communication in sequence. The implementation method of the digital front end system comprises the following steps: 1, a modulation symbol is input to the transmitter and converted into an analog signal; 2, the analog signal is input to the receiver and converted into the modulation symbol. The digital front end system used for the power line carrier communication and the implementation method of the digital front end system combine a digital front end in the form of an equivalent complex number base band with a Nyquist windowing method, and have the advantages of supporting frequency band selection and bandwidth configuration, suppressing out-of-band interference, reducing sending signal out-of-band energy, and suppressing in-band narrow-band interference.