The invention relates to the technical field of furniture and particularly relates to a demountable chair. The demountable chair consists of a chair body, a seat supporting frame and chair legs, wherein the chair body comprises a seat which is used for undertaking the hip-thigh part of a human body, the upside of the seat supporting frame can be detached from the seat, the downside of the seat supporting frame can be detached from the chair legs, the seat supporting frame comprises a load bearing frame, which is provided with a flat upper surface and is formed through interconnecting four hollow metallic tubes, and supporting bodies which are fixed to the lower surface of the load bearing frame and are used for being connected with the chair legs, the four hollow metallic tubes are of an arc concave shape towards the center of the load bearing frame, the concave hollow metallic tubes are in end-to-end connection sequentially, and structures that adjacent hollow metallic tubes are abutted with one another by sidewalls are formed at junctions; the upper ends, in the vertical direction, of the supporting bodies are welded to the lower surfaces of the bottom walls, adjacent to abutted sidewalls, of adjacent hollow metallic tubes. The demountable chair has the advantages of simple and firm structure, strong carrying capacity, difficulty in deformation, convenience in production, convenience in demounting and low cost.