The embodiment of the invention belongs to the technical field of bicycle high-speed roads and provides a bicycle high-speed overhead viaduct and a construction method thereof. The overhead viaduct comprises a plurality of pier columns, a plurality of steel cover beams and a plurality of steel box beams. The multiple pier columns are arranged at intervals and welded to a foundation. The lower ends of the middles of the steel cover beams are welded to the upper ends of the pier columns. Each steel box beam is welded between the corresponding two adjacent steel cover beams. The pier columns are installed on the foundation, the steel cover beams are welded to the tops of the pier columns, and the steel box beams are welded between the steel cover beams in a butting mode, so that bicycle high-speed overhead viaduct is formed, riders can rapidly ride on the overhead viaduct, riding experience is good, travelling is convenient, existing resources are fully utilized, and the cost is reduced.