The invention relates to an asteroid orbital transfer method. According to the asteroid orbital transfer method, an asteroid orbit is changed through a tether formation flight system composed of a solar sail and an asteroid. The asteroid orbital transfer method comprises the steps that the solar sail backwards and horizontally throws out a tether lock connected with a tether, the solar sail captures the tether lock after circling the asteroid for a circle, and is in butt joint with the tether lock, and then the tether is retracted so that the tether can be bound to the surface of the asteroid; the solar sail is thrown off through autorotation of the asteroid; the light pressure borne by the solar sail is adjusted by adjusting the posture of the solar sail, acting force is transmitted to the asteroid through the tether, and the autorotation speed of the asteroid is gradually reduced through the acting force; after the autorotation speed of the asteroid is reduced, the asteroid is transferred to a low-energy transfer orbit through adjustment of the posture of the solar sail. The asteroid orbital transfer method has the advantages that the threat caused by the asteroid to the earth is removed, the structure and the ingredients of the asteroid cannot be damaged, long-term orbital transfer can be carried out, and therefore the asteroid can be controlled to serve as a transfer station for interplanetary exploration of the human.