Railway subgrade subsidence monitoring system and method

The invention discloses a railway subgrade subsidence monitoring system which comprises trackers, an unmanned aerial vehicle monitoring system and a data control system. Each tracker comprises a magnetic field transmitting element used for exciting a magnetic field. The unmanned aerial vehicle monitoring system comprises an unmanned aerial vehicle, a GPS arranged on the top of the unmanned aerial vehicle and triaxial magnetic sensing probes located on the left wing and the right wing of the unmanned aerial vehicle, the unmanned aerial vehicle flies above laid sections of the trackers along a railway line, and the triaxial magnetic sensing probes are used for receiving magnetic induction intensity excited by the trackers. The data control system processes monitoring information of the unmanned aerial vehicle monitoring system into deep deformation of a subgrade and carries out early warning on railway subgrade subsidence. The invention further discloses a monitoring method for using the railway subgrade subsidence monitoring system. According to the monitoring system and method, large-scale cruise type railway subgrade subsidence monitoring is achieved, the problems that railway subgrade deep subsidence is difficult to monitor and monitoring needs to span super-long railway lines are solved, and the requirements for all-weather operations are met under severe environments such as outdoor areas, waste mountains, plateaus and alpine regions.