The invention relates to a caterpillar band tensioning device. The caterpillar band tensioning device is provided with a hydraulic cylinder with an oil outlet valve, an elastic component coaxial withthe hydraulic cylinder, a floating piston coaxial with the elastic component, a piston arranged at one end of the oil outlet valve of the hydraulic cylinder and provided with an oil inlet valve, and aswitch valve for controlling the working mode of the hydraulic cylinder. The hydraulic cylinder is controlled through the switch valve, and therefore the functions that according to the working condition, real-time compensation of caterpillar band tensioning force is achieved, collision of an inducing wheel on the ground is buffered, caterpillar band vibration is restrained, the inducing wheel islocked during braking, and a caterpillar band is actively tensioned are achieved. The hydraulic system is started only when the caterpillar band is actively tensioned, low pre-tightening force can beset according to other working conditions, and therefore the caterpillar band power dissipation and the control power dissipation can be greatly reduced.