The utility model relates to an angle steel assemblage measuring apparatu relates to and measures technical field, and main aim at improves the efficiency of the assemblage of angle steel. The main technical scheme who adopts does: angle steel assemblage measuring apparatu is including support piece, a laser emitter, location connection structure and spirit level, a laser emitter sets up support piece is last for launch first laser ray, location connection structure is used for connecting support piece and outside equilateral angle steel, the location connection structure can keep first laser ray is located on outside equilateral angle steel's the plane of symmetry, and with outside equilateral angle steel's length direction is perpendicular, the spirit level sets up support piece is last, is used for instructing support piece's rotation angle. The utility model discloses angle steel assemblage measuring apparatu is applicable to and fixes a position the angle steel at equilateral angle steel assemblage in -process.