Roller bed and horizontal rotation table in-position device and method

The invention relates to a field roller bed and horizontal rotation table in-position device and method which are suitable for arranging an engine production line field roller bed and an engine production line field horizontal rotation table in place. A positioning template is placed on the conveying roller bed or the horizontal rotation table and provided with openings. Plumb lines of two line pendants pass through the openings in the positioning template correspondingly to position the line pendants, two points are connected into a line, the connecting line between two line pendant sharp ends is the conveying center line of the roller bed or the horizontal rotation table, the line pendants are attached to the ground, and after the two line pendants are static, whether the points, projected to the ground, of the sharp ends of the two line pendants are located on the drawn center line in a workshop or not is very easily observed, wherein if the points, projected to the ground, of the sharp ends of the two lin