A system and a method for draining soft soil A bordered with soil B are disclosed. The system includes an airtight sheet 10 which covers the soft soil A to assist in vacuuming the soft soil A. The system further includes water gathering pipes 13 and a water drain tank 16 to receive water from the water gathering pipes 13. The water gathering pipes 13 and the water drain tank 16 provide water passages and air passages separately so as to expedite the drainage operation.