An embodiment of the invention relates to a system for coupling carrier null lines of broadband power lines of power distribution areas. The system comprises a centralized carrier module, a first high-frequency coupling magnetic ring and terminal carrier modules. The centralized carrier module is mounted in a power centralized acquisition facility and can be powered by the power centralized acquisition facility; two ends of a conductor of the first high-frequency coupling magnetic ring are connected with carrier output ports of the centralized carrier module, and the first high-frequency coupling magnetic ring sleeves the null lines between earth connecting points and terminal facilities; the terminal carrier modules are mounted in the terminal facilities and are coupled with the power lines; the terminal facilities are communicated with the centralized carrier module via the terminal carrier modules. The system for coupling the carrier null lines of the broadband power lines of the power distribution areas in the embodiment of the invention has the advantages that the null lines can be coupled, accordingly, the shortcoming of characteristics of low impedance of circuits can be overcome by the aid of injection modes in current forms, and the communication success rate can be guaranteed.