The invention discloses a well irrigation and salt restraint device and method for drainage water recycling, and belongs to the technical field of soil improvement. The device comprises a main well, an upper-layer pipe group and a lower-layer pipe group, wherein the main well comprises a water-permeable outer-layer well wall, a water-impermeable inner-layer well wall sleeving the outer-layer wellwall, and a water conveying layer between the outer-layer well wall and the inner-layer well wall. The upper-layer pipe group is communicated with the upper portion of the outer-layer well wall and ispermeable to water, the lower-layer pipe group is communicated with the lower portion of the inner-layer well wall, a near-well section of the lower-layer pipe group is impermeable to water, and a far-well section of the lower-layer pipe group is permeable to water. The upper-layer pipe group and the lower-layer pipe group are responsible for salt restraint and drainage water recycling respectively, the amount of water used for salt leaching can be reduced, and the loss of nutrient substances such as nitrogen and phosphorus is avoided; meanwhile, by means of drainage water recycling, the problem about irrigation water resources is solved, and salt-containing water obtained after salt leaching is treated. In conclusion, irrigation and salt leaching can be supplemented in a short term, theunderground water level can be reduced in a long term, salt accumulation of the high underground water level is blocked, and the dual purposes of irrigation and salt restraint are achieved.