PURPOSE: To omit a specific driving source to rotate a turntable, and to simplify the structure of the turntable so as to reduce the cost, as to a direction changing method and device of a truck self-traveling on a track.

CONSTITUTION: At the position to change the direction, a part of a track is provided, and a turntable 31 rotatable to the set surface and a fixed table 34 for converting fixed to the set surface at the center of the turntable 31 are provided. To a truck 3 self-traveling on the track, a roller 21 for turning driven to rotate by a driving source (driving motor) 14 for self traveling is provided, and when the carriage 3 is loaded on the track of the turntable 31, the running of the truck 3 is stopped, and by driving to rotate the roller 21 for turning in the condition to abut the roller for turning to the upper surface 34b of the fixed table 34 for converting, the turntable 31 is rotated so as to convert the direction of the truck 3.