The invention relates to a broadband communication device, in particular to the broadband communication device for a 35kV-voltage level line-based long-distance high-speed power line. The broadband communication device is structurally characterized in that: a signal transmitting device of the broadband communication device is connected to a 35kV-voltage level power line through a coupling device; a signal receiving device is a wireless receiving device; and the output end of the signal receiving device is connected with a data processing module. The broadband communication device has the advantages that: in the broadband communication device, first, signals are coupled to the power line in a wired way, then, radio carrier signals are transmitted to space according to features of the high-voltage power line, and finally, radio signals are received in a wireless way, so that technical prejudices in the field are overcome; the communication distance is expanded over 8 kilometers successfully and effectively; and the broad communication of the power line with a first-stage relay of 14.5 KM is realized.