The invention discloses a mechanical structure of powdered material selectivity laser sintering molding equipment. The mechanical structure comprises a rigid supporting frame, a laser and light path guide system and a circuit system, a laser sintering molding region arranged below the laser and light path steering system and the circuit system, a chalk box, a vertical driving device and a shell, wherein the laser and light path guide system and the circuit system are arranged on the upper part of the rigid support frame, the chalk box and the vertical driving device as well as the shell are arranged below the laser sintering molding region, and the whole rigid supporting frame is formed by hollow stainless steel square pipes through welding. According to the invention, since the structure is adopted, the SLS (selective laser sintering) technology is effectively and subtly realized, the environmental requirement (temperature: 0 DEG C---35 DEG C, humidity: 10%---95%) of the equipment and a working condition in a forming process are greatly reduced compared with the same SLS technology; and the design of the mechanical structure enables the volume of the equipment of the SLS technology to be reduced by at least 30%, and the weight is lighter, therefore, the manufacturing cost is reduced, and the equipment is more convenient to maintain and operate.