Urban rail train and transmission circuit of train hard line signal of urban rail train

The invention discloses a train rigid line signal transmission circuit. The circuit comprises a first storage battery, a first connector, a second connector, N key signal switch units, a first electric signal receiving part and a second electric signal receiving part, wherein a first end of the first connector is connected with the first storage battery, a second end of the first connector is connected with a first end of the first connector, the N key signal switch units are connected in series between the second end of the first connector and a second end of a second connector, the N is a positive integer, a third end of the second connector is respectively connected with the first electric signal receiving part and the second electric signal receiving part, and the second end of the second connector is connected with the third end of the second connector. The circuit is advantaged in that stability of the circuit is improved, and cost is reduced. The invention further provides an urban rail train which has