The light steel villa utilize the 100% cold-bend thin wall steel as the structure body and can be used to build buildings within 6 floors. The main building component of this system is the frame bridge,which is composed by the galvanized cold-bending high frequency welded light thin wall rectangular pipe and the triangle.C type, triangle v type connection. All these prefabricated components are transferred to the construction site to be installed into the structure body. After that the interior, exterior wall panels and roof profile panels are laid out, while the heat and sound insulation material are filled into the space in the wall and floor deck. This product solve the problem of “hot bridge,bad fire resistance”.