The invention relates to water connection plates, in particular to a water connection plate of a train power supply cabinet of a power-centralized motor train unit. The problem that an existing trainpower supply cabinet water connection plate is not suitable for the water connection using environment between a train power supply cabinet power module and a water circulation system of the power-centralized motor train unit due to the fact that the existing train power supply cabinet water connection plate is limited by the mounting space and the self weight is solved. According to the scheme, the water connection plate of the train power supply cabinet of the power-centralized motor train unit comprises a connection plate body with a fastening screw being screwed at the center, concave tables are machined at the two ends of the connection plate body, water connection rapid plugs penetrate through the concave tables, and positioning guide columns penetrate through the inner sides of thewater connection rapid plugs. The water connection plate of the train power supply cabinet of the power-centralized motor train unit has the advantages that 1, the structural design is ingenious, andpositioning is achieved rapidly and accurately; 2, the water connection plate can be rapidly plugged in and pulled out, and is convenient to mount and maintain; and 3, the structural size and the selfweight meet the overall weight reduction requirements of power-centralized electric locomotives.