An improved construction pillar insertion combination rack made of metal wire material in a rectangular or polygonal form and in a single layer or multiple layers includes multiple side frames, multiple pillars, multiple clamping members, and a top; each limitation corner of the rack comprised of two rings concentrically arranged with the diameter of the upper ring smaller than that of the lower ring; each side frame including an upper and a lower support rods; a connection rod usually made in a waveform being disposed at where between and soldered to both of the upper and the lower support rods; each pillar containing multiple sections with a circumferential slot being defined by any two abutted sections; the pillar being secured with the clamping member at where it to be inserted into the limitation corner; and the top usually related to a mesh being placed on the frame of the rack; alternatively, an upper frame with multiple upper rings of the limitation corner and a lower frame with multiple lower rings of the limitation corner may be separately made in continuous form to be spot soldered at where both ends meet.