Reinforcing structure of existing pier and construction method

The invention discloses a reinforcing structure of an existing bridge pier and a construction method, and belongs to the technical field of bridge reinforcement, the reinforcing structure comprises the bridge pier and a bearing platform, the bridge pier and the bearing platform are connected with longitudinal bars, the bridge pier is provided with a steel hoop, and the peripheral side of the steel hoop is detachably connected with a plurality of uniformly distributed fixing ends; a plurality of grooves distributed in a circular array are formed in the bearing platform, and a plurality of mounting seats corresponding to the fixed ends are fixed in the grooves; shape memory alloy bars are connected between the fixing ends and the mounting bases and sleeved with supporting cylinders, sealing plates used for sealing the grooves are fixed to the supporting cylinders and attached to the bearing platform, the tops of the supporting cylinders are detachably connected with the fixing ends, and the bottoms of the suppo