Drag train signal transmission method and apparatus

The present invention provides a signal transmission method and a plant train apparatus, the method comprising: S1: receiving a first signal sent via the line across the bridge, the first extracting a first data signal carried; S2: wirelessly receiving hair to the first signal and the second signal corresponding to the second signal to extract the second data carried; S3: determining whether the first data and the second data are identical, if so, output said first signal, otherwise, outputting said second signal. Drag train signal transmitting method and apparatus provided by the present invention, improves the reliability of the transmission signal train plant.