To provide a truck connection device, a truck connection structure and a truck control method capable of preventing any rattling of a truck in traveling while facilitating positioning when the truck is stopped.

The truck connection device 31 comprises a connection mechanism 32 for connecting adjacent conveying trucks to each other in a relatively displaceable manner, and a displacement regulating device 33 for regulating the relative displacement of the conveying trucks to be connected. The connection mechanism 32 comprises a pair of stoppers 38 having base parts 36 provided on the adjacent conveying trucks and connection members 37 for connecting the base parts 36 while one base part 36a is separately provided in the connecting direction of the conveying trucks, a supporting member 39 provided between the pair of stoppers 38 in a displaceable manner in the connecting direction of the conveying trucks, and a pressing mechanism 41 for selectively pressing the supporting member 39 against any one of the pair of stoppers 37 and fixing it thereto. The connection member 37 is connected to one base part 36a via the supporting member 39.