The invention relates to a space bending porous superstructure with an adjustable sound absorption frequency band and low-frequency broadband sound absorption performance. The space bending porous superstructure comprises a left side plate, a right side plate, an upper panel, a bottom lining plate, a partition plate and a porous sound absorption material, wherein the left side plate, the right side plate, the upper panel, the bottom lining plate and the partition plate form a space bending channel, and the porous sound absorption material is embedded in the space bending channel. Under the condition that material thickness is not increased, the propagation path of sound waves is greatly increased, and sound energy loss is increased, so the superstructure has excellent low-frequency sound absorption performance; the superstructure has the advantage of large absorption bandwidth, and when the wave crest frequencies are similar, the superstructure has a sound absorption coefficient of 0.8 or above and has bandwidth of 220 Hz; a sound absorption frequency band can be adjusted by adjusting the channel number or channel layout of a space bending structure, and low-frequency broadband sound absorption can be achieved by arranging units of different sound absorption frequency bands in parallel; and the superstructure is simple in structure, easy to produce and low in cost, and has wide engineering application prospects in a low-frequency noise field.