The invention provides an automatic bridging system. The automatic bridging system uses a single bridging unit as a main body, wherein each bridging unit comprises a moving platform, a support module, a regulating platform and an intelligent operating platform. A using method of the automatic bridging system comprises the following steps: firstly, the bridging system supports a prefabricated component on one vertical-crossing sides of piers, and then the regulating platforms rotate by a certain angle, so that the prefabricated component rotates together; support columns of the regulating platforms support the prefabricated component, and after the height of the prefabricated component exceeds supporting structures at the upper parts of the piers, the regulating platforms rotate; when the prefabricated component and the vertical crossed diameter of the piers are parallel and arranged on a plane which is perpendicular to a level surface, the support columns fall until the prefabricated component is close to the pier supporting structures. The automatic bridging system disclosed by the invention has the characteristics of high intelligence, high automation, high precision and the like. The automatic bridging system disclosed by the invention is not limited by bridges, and the clearance height above overheads.