The invention provides an induction hardening rapidly aligning method of a brake cam. A rapidly aligning device comprises an inductor, a brake cam and an auxiliary positioning device. The inductor isprovided with a containing cavity, the brake cam can be rotatably arranged in the containing cavity of the inductor, and the shape of the outer wall of the brake cam corresponds to the shape of the inner wall of the inductor; the inner wall of the inductor is used for forming the containing cavity, the auxiliary positioning device is provided with two positions, one of the two positions is an aligning position, the other one of the two positions is a hardening position, the auxiliary positioning device can be rotatably arranged on a hardening machine tool working table, and the auxiliary positioning device can be switched between the aligning position and the hardening position in the rotating process; and when the auxiliary positioning device is located on the aligning position, the auxiliary positioning device acts on the brake cam, and therefore the distance between the outer wall of the brake cam and the inner wall of the inductor is consistent.