PURPOSE: To effect follow-up-work of blades on a road surface by arranging a cylinder for regulating the grounding pressure and balance of the blades, and a cylinder for regulating a cutting angle, in a snow removing truck, and by controlling each fluid pressure automatically.

CONSTITUTION: The grounding pressure and the left and right grounding pressure balance of blades arranged on the lower surface of the central section of a car body are regulated by a pair of hoist fluid pressure cylinders 2, an the cutting angle of the blades is regulated by a reverse rotation fluid pressure cylinder 3. Then, a set value for input provided by a setting device 4, the grounding pressure signal of a hoist pressure sensor 5 for sensing the fluid pressure of the cylinder 2, and the cutting angle signal of an angle sensor 6 for detecting a relative position between the present angle and gravity working direction of the blades, are compared with each other by a comparator 7. After that, a blade grounding pressure regulating means 9 and a blade angle regulating means 10 are worked.