To enable smooth wiring between vehicles by using a wiring connection box.

The wiring connection box 4 is supported by a link bar 11 connecting a front side vehicle and a rear side vehicle. Receiving connectors 22A-22E to which end connectors 21A-21E of wiring cables C11-C15 of the front side vehicle and the rear side vehicle are connected are provided on a front side surface and a rear side surface of the wiring connection box 4. Connection cables 23A-23E connecting front side surface side receiving connectors 22A-22E and rear side surface side receiving connectors 22A-22E are provided inside of the wiring connection box 4, and wiring cables C11-C15 of the front side vehicle and the rear side vehicle are connected each other via the connection cables 23A-23E.