Power line state monitoring method and device

The invention provides a monitoring method of a power transmission line state in a power line communication system, wherein the monitoring method comprises the following steps: S1. a node A performs framing on the known training sequence and to-be-sent data modulated by an OFDM (orthogonal frequency division multiplexing) technology, and sends signals into a power line through a coupler for transmission; S2. a node B receives sent signals through the coupler, modulates the received signals by utilizing the known training sequence, and extracts transmission data; S3. the node B obtains transmission channel frequency response or impact response by utilizing the known training sequence; S4. the node B analyzes the channel frequency response, extracts relevant information of the transmission line, and obtains the variation information of basic parameters of the transmission line through analyzing the relevant information so as to calculate the channel parameters; and S5. the node B estimates and forecasts the channel state of the power transmission line according to channel parameter variation. According to the method provided by the invention, the state information of the power line can be monitored in real time, and a data collecting device and a communication system are not required to be arranged out of the power transmission line, and the monitoring method of the power transmission line state in the power line communication system has the advantages of good stability, low cost, and the like.