The invention discloses a memorial archway type tension leveler. The memorial archway type tension leveler comprises a memorial archway type frame, at least two sets of tension-straightening rollers and lifting driving mechanisms, wherein the memorial archway type frame comprises a base, an upper framework and a plurality of rows of stand column frames, each set of tension-straightening rollers are located between two adjacent rows of stand column frames, and comprise one upper tension-straightening roller and one lower tension-straightening roller, the lifting driving mechanisms are installedon the upper framework, the number of the lifting driving mechanisms is the same as the number of the sets of the tension-straightening rollers, displacement sensors are installed on the upper portions of the lifting driving mechanism, the lower portions of the lifting driving mechanisms are connected with upper tension-straightening roller lifting frames, the upper tension-straightening rollersare rotationally arranged in the upper tension-straightening roller lifting frames, the lower tension-straightening rollers are rotationally installed on the stand column frames, sliding rails are arranged on one sides, facing the tension-straightening rollers, of the stand column frames, and the lifting driving mechanisms drive the upper tension-straightening roller lifting frames to slide up anddown in the sliding rails. The memorial archway type structure is simple and compact, is good in framework rigidity and has a stable guiding function, the reduction amount is controlled accurately, and the quality of a casting blank is guaranteed. The invention further discloses a small square billet continuous casting machine applying the memorial archway type tension leveler for reduction.