The invention discloses a slope ramp steel box beam conveying vehicle and method. The beam conveying vehicle comprises two parallel brackets which are in parallel connection through a truss. Each bracket comprises an upper chord and a lower chord, wherein the upper chord and the lower chord form an acute included angle and are connected through a plurality of stand columns and oblique supporting rods in a welded mode; and a plurality of shoulder pole beams are welded between the tops of the upper chords, and rollers are arranged at the bottoms of the lower chords. During beam conveying, a rail foundation platform is constructed on and guide rails are laid on a slope between a shore and a steel box beam installation lifting point, the beam conveying vehicle is placed on the rails, steel box beams are lifted and placed on the beam conveying vehicle from a beam conveying ship, and a winch is used for hauling the beam conveying vehicle to the position below the steel box beam installation lifting point.