The invention discloses a steel trestle construction method for resisting the impact of flood discharge rapids. The steel trestle construction method comprises the steps that a foundation comprises large and small steel pipe piles arranged at intervals in the longitudinal bridge direction, and hoop type joint systems are installed between the adjacent steel pipe piles in the transverse bridge direction; bottom openings of the small steel pipe piles are inserted into a rock surface in a piling mode, and distributive beams are embedded in the bottom openings of the small steel pipe piles throughpile top grooves to be tightly attached to a trestle main beam; after bottom openings of the large steel pipe piles are inserted into the rock surface in a piling mode, temporary brackets are weldedto both sides of pile bodies in the bridge axial direction, then distributive beams are placed to be tightly attached to the trestle main beam, when the trestle bridge is assembled to the front of therow of steel pipe piles with a length of not less than 2 times of a hole span, a percussion drill is arranged at the position, at the row of steel pipe piles, on the trestle main beam, the large steel pipe piles are used as pile casings for milling holes and following up to the designed elevation in a rock stratum, the temporary brackets are cut off, formal brackets are rewelded, top openings ofthe large steel pipe piles are cut to be flush with the trestle main beam, and the lower ends of the large steel pipe piles are filled with underwater concrete to form anchor resisting piles. The steel trestle construction method for resisting the impact of the flood discharge rapids is rapid in construction and rapid in formation of water passages, anchor resisting pile construction is performedon land, the working environment is good, and capital investment is low.