The utility model discloses a caterpillar band tensioning device of a hillside caterpillar tractor. The caterpillar band tensioning device comprises a supporting belt wheel set, a movable supporting rod, a tensioning spring, a tensioning hydraulic cylinder, a hydraulic cylinder fixing base, a trolley frame, a guide plate, a guide rail, a guide wheel and a guide wheel support. The horizontal position of the guide wheel is changed through stretching and retracting of the tensioning hydraulic cylinder, the vertical position of the track supporting wheel set is changed through stretching and retracting of the tensioning spring, and therefore tensioning of the track is achieved. The device is compact in structure, easy to operate and high in practicability, and has good application and popularization value.