Grounding system of rail train and rail train

The embodiment of the invention provides a grounding system of a rail train and the rail train. The grounding system of the rail train comprises a gear box grounding device and a grounding resistor, wherein the gear box grounding device is assembled on a collector ring box on the outer side of a gear box of a power bogie; the gear box grounding device is used for collecting leakage current from a collector ring in the collector ring box, and the leakage current collected from the collector ring is conducted to a rail to be grounded through a wheel set assembled on a gear box; one end of the grounding resistor is connected with a train body of the train through a wire, and the other end of the grounding resistor is used for being connected with the gear box grounding device through a wire; and leakage current of the train body of the train is conducted to a rail bar of the rail through the grounding resistor, the gear box grounding device and the wheel set to achieve grounding. The rail train comprises the gro