Distributed acoustic wave train wheel rail detection device and method

The invention provides a distributed acoustic wave train wheel rail detection device and method. The device comprises an optical cable and a light transmitting and receiving module, the optical cableis arranged at a noise source close to an acoustic wave generation signal and comprises a sensing optical cable and an access optical cable, a plurality of parallel optical fiber cores are sequentially connected end to end to form the sensing optical cable, the head end of the access optical cable is connected with the tail end of the sensing optical cable, the light transmitting and receiving module comprises a light source and a light receiver, the light source transmits a first pulsed light signal into the optical cable through an acoustic optical modulator, the light receiver is connectedwith the tail end of the access optical cable and probes backward scattered light reflected from a plurality of positions of the optical cable, so that the signal to noise ratio is improved, sensitivity in wheel rail vibration