The utility model discloses a pier and abutment dry installation structure which comprises a steel structure cylinder, a caisson, underwater concrete, a pile foundation, a prefabricated pier and abutment and backfill. The steel structure cylinder is installed on the caisson through a fastening device, and the steel structure cylinder and the caisson are matched to form a cofferdam water stop structure. Reserved holes are formed in a bottom plate of the caisson, abutment pile foundations penetrate into the reserved holes, underwater concrete is poured into cabin lattices, penetrating into the pile foundations, of the caisson, and water stopping between the caisson and the pile foundations is achieved; backfill materials are added into other cabins, and after underwater concrete meets the strength requirement, water in the steel structure cylinder is pumped to the position 1 m below the elevation of the to-be-installed bottom of the abutment, so that assembling of the bottom-supported cofferdam water stop structure is completed; after water is pumped in the cofferdam, a prefabricated abutment is installed at the upper end of the pile foundation, and a post-pouring hole is poured between the prefabricated abutment and the pile foundation. According to the bottom-supported cofferdam water stop structure, large-scale vibration sinking/vibration pulling equipment is not needed in themounting and dismounting process, no water stop requirement exists for a soil layer, and the problem that medium-coarse sand layers and other geology are difficult to insert does not exist.