The load-bearing structure of light steel structure residential building adopts cold-formed thin-walled light steel skeleton, adopting high-strength and anti-corrosion steel coil plate (yield strength 550Mpa, zinc-aluminum alloy coating thickness 270g/m'), steel thickness is 0.75mm or higher, through computer controlled equipment for manufacturing is directly rolled into various types of structural member according to design requirements. The vertical load-bearing members of the whole structure adopt densely packed columns, the maximum column spacing is 600mm; the plane load-bearing members and roofs adopt the purlin net, the grid size is 600x600mm; the floor (ground) surface adopts the truss beam, the maximum medium distance is 1200mm, the doors and windows beams are made of small truss. The whole process of production of steel structure is completed by professional equipment controlled by computer software which ensures the precision of component manufacturing and realizes the change of the millimeter error of traditional building mode to the millimeter error of factory manufacturing. Cold-formed thin-walled steel members withstand relatively large external 1oads with relatively few materials, not simply by increasing the cross-sectional area, but by changing the cross-sectional shape. According to the calculation, the cold-bending thin-walled steel with the same cross-sectional area can be increased by 80% compared with the hot-rolled steel, and the moment of inertia and the area moment can be increased by 50-180%. Considering the cold-bending effect of the material, it can generally be improved. The design strength is 10-15%.