Alignment device and method for large-diameter roller bed

The invention discloses an alignment device and method for a large-diameter roller bed. The alignment device comprises a magnetic base, a rocker arm and a micrometer rod, wherein the magnetic base is attracted to the end face of the large-diameter roller bed, the rocker arm is installed on the magnetic base, one end of the rocker arm stretches out of the end face of the roller bed, and the micrometer rod is installed at the end, far away from the magnetic base, of the rocker arm. The magnetic base is in a switching magnetism type. Magnetism of the magnetic base is switched through a switch of the magnetic base. The micrometer rod is installed on the rocker arm through a pipe clamp. By means of the alignment device for the large-diameter roller bed, the problems that when a large-diameter roller bed is aligned in a conventional mode, a fixing supporting frame is poor in universality, a large number of materials are wasted, operation is complex, consumed time is long.