To provide a vehicle connection device capable of maintaining self-traveling vehicles arranged in tandem with a predetermined gap.

A ball screw 3 is pivotally supported on an outer cylinder 2 connected to a rear end of the self-traveling vehicle 7 of rank head and a nut 5 thread-engaged with the ball screw 3 is fixed to an inner cylinder 4 connected to a front part of the following self-traveling vehicle 9. A disc brake 6 capable of restricting rotation of the ball screw 3 and a controller 14 for adjusting vehicle speed when a gap of the front and rear self-traveling vehicles 7, 9 is varied are installed. Namely, rotation of the ball screw 3 is restricted by the disc brake 6 to suppress movement of the nut 5 and the gap of the self-traveling vehicles 7, 9 is fixed. Alternately, the vehicle speed is adjusted by the controller 14 to immediately stop variation of the gap of the self-traveling vehicles 7, 9.