The invention discloses an H-shaped section fabricated buckling-restrained brace component, which belongs to the technical field of structural engineering. The component consists of an H-shaped kernel component and a peripheral restraint component. The H-shaped kernel component comprises three steel plates by welding, and hard rubber is stuck to the surface of the H-shaped kernel component. The peripheral restraint component consists of two square rectangular pipes and two flat steel plates by binding, or consists of four square rectangular pipes by binding. The binding effect is realized by performing high-strength bolt connection on each restraint component; the high-strength bolt passes through the bolt holes on the restraint components and the steel base plates and a plurality of rubber gaskets arranged among the restraint components, and connects the four restraint components together. The thickness of the steel base plate is more than the thickness of the flange of the H-shaped kernel component, and the thickness of the rubber gaskets is adjusted so that a 1 to 2 mm gap is kept between the surface of the restraint component and the surface of the H-shaped kernel component under the pre-tightening force of the high-strength bolt, wherein the gap is filled with the hard rubber stuck on the surface of the H-shaped kernel component so as to meet the requirements of transverse expansion of the H-shaped kernel component expanding under pressure.