Construction process for replacement of large-tonnage bridge support

The invention relates to the field of building construction, in particular to a construction process for replacement of a large-tonnage bridge support. The process comprises the steps that firstly, manholes of diaphragm plates in box girders are temporarily and locally reinforced, a temporary support is arranged, jacks are placed, counter-force replacement is completed when no vertical displacement of fulcrums of girder bodies is achieved, and the temporary support and an old support are subjected to joint load carrying; and then a method of reverse construction is adopted, a padstone of the old support is cut and removed, a new support is installed, the temporary support is released, the counter-force replacement of the new support and the old support is completed, and thus the replacement work of all old supports is completed. The construction process for the replacement of the large-tonnage bridge support is mainly applied to the replacement construction process of the large-tonnageold supports, the old su