Construction method for hoisting new viaduct based on original bridge

The invention relates to a construction method for hoisting a new viaduct bridge based on an original bridge, and the method specifically comprises the following steps: building a temporary support, enabling hoisting equipment to enter a site, enabling a steel beam to enter the site, hoisting the hoisting equipment, aligning and splicing the steel beam, detecting the size of the steel beam, welding the steel beam, detecting a welding seam, and removing the temporary support. The hoisting equipment comprises a hoisting base, a clamping table lifting device arranged on the hoisting base and a clamping table which is arranged on the clamping table lifting device and can move in the vertical direction. The clamping table comprises an edge clamping plate, a plurality of sets of clamping blocks which are connected to the edge clamping plate in an opposite sliding mode and clamp the two side edges of the steel box girder in the length direction, and a clamping block opposite moving mechanism which is arranged on the