Pure steel type buckling restraint support

The invention discloses a steel structure buckling restraint support, and particularly relates to a pure steel type buckling restraint support. An outer sleeve, inner sleeves and core plates are included. The inner sleeves are arranged in an inner through hole of the outer sleeve in a left-right symmetry manner. An inserting connection piece is arranged between the two inner sleeves. The two endsof the inserting connection piece are inserted in the left inner sleeve and the right inner sleeve correspondingly. The inserting connection piece is fixedly connected to the inner walls of the innersleeves. Gaps are formed between the inner sleeves and the outer sleeve. The outer surfaces of the inner sleeves are closely attached to the inner surfaces of the core plates. Each core plate is formed by two perpendicular side plates, wherein the two side plates are outwards provided with same weakening section grooves correspondingly. A gap is formed between each core plate and the outer sleeve.The core plates are fixedl