Laying high voltage cable in public transportation tunnels has gradually become a development direction for the integration construction of large tunnels and integrated pipe gallery. Adoption of regular length of cable in the tunnels crossing river and sea has such disadvantages as excessive connectors and grounding point as well as complicated grounding system. Laying the long distance and large section cable can reduce the number of grounding point and number of connectors under the water

reduce construction cost and improve the stability of system. In this paper

the Nanjing Yangtze River channel is taken as the carrier in this paper

the mutual influence between other pipeline and the high voltage cable in the tunnel

in case of laying long distance segment high voltage cable in the public transportation channel

is studied

which can provide reference for the specific implementation of laying high voltage transmission cable for public transportation tunnels.