Abstract: Due to the single means of rail transit stray current monitoring, it can not reflect the safety status of reflux system effectively. In the paper, a new stray current dynamic monitoring system is proposed, the solution measures like monitoring functions and methods, structural framework and key technologies of the system are introduced. In which the monitoring of the stray current leakage value and the rail to earth transition resistance is taken as the main monitoring scheme, to provide reference for the construction of subsequent rail transit lines.