The invention discloses a refuse landfill percolate pump drainage minor-caliber shaft structure and a silt prevention maintenance method. The shaft is composed of galvanized steel pipes, the lower section of some is not provided with holes, the whole middle section cylindrical surface of some is provided with through holes and the upper section of some is not provided with holes, both the galvanized steel pipes with lower section not provided with holes and the galvanized steel pipes with middle section provided with through holes are coated with soil engineering composited drainage meshes. The holes of the galvanized steel pipes are mounted with discharging tubes and compressed air tubes, the mouths of the galvanized steel pipes with upper section not provided with holes are provided with flanges, one end of each compressed air tube is inserted into the hole of discharging tube and the other penetrates through the flange. The mouth of discharging tube is divided into three paths, thefirst path is communicated with a sewage sucking pump via the valve of the sewage sucking pump, the second path is communicated with a clean water pump via the valve of the clean water pump and the third path is communicated with the drainage port via the valve of the drainage port. The manufacture cost of the invention is obviously lower than major-caliber shaft, the holes can be drilled by common drillers, the construction period is short, and the shaft structure can be used for forward and backward washing and maintenance for silt prevention and has good leakproofness and corrosion resistance.