External prestressing system of UHPC (Ultra High Performance Concrete) composite beam and construction method of external prestressing system

The invention discloses an external prestressing system of a UHPC (Ultra High Performance Concrete) composite beam and a construction method of the external prestressing system. The external prestressing system comprises an external prestressing tendon in the UHPC composite beam, an external prestressing tendon embedded pipe in a fulcrum heightening area and an anchoring tooth block, a bridge deck of the UHPC composite beam comprises a steel bottom plate with a PBL shear key on the upper portion and a UHPC panel. The steel bottom plate comprises a flat bottom plate and side bottom plates, and a bridge deck fulcrum heightening area is defined by the adjacent side bottom plates above the steel main beam transverse partition plate. The two ends of the external prestressing tendon are anchored to the anchoring tooth blocks. An external prestressing tendon penetrates through the embedded pipe on the fulcrum heightening area; the anchoring tooth block comprises a tooth block end plate, a tooth block bottom plate, t