Hongtai can protect the cross-corrosion of the girder where the track is located through the dry air circulation of the truss. Compared with the high cost of anti-corrosion coatings and the expensive charge of the bridge maintenance and weight increase, dehumidifier requires minimal maintenance and can save time. At the same time, corrosion protection is also required for corners that are difficult to take care of, so dry air is indeed the preferred method.