The invention discloses a method for treating a foundation by a vacuum prepressing method through positionable water permeable pipes, and belongs to the field of geotechnical engineering. The method comprises the following steps of (1) leveling a site; (2) paving a sand cushion; (3) performing measurement to determine hole positions of the water permeable pipes, and arranging the positionable water permeable pipes to a designed depth in an inserting manner; (4) laying vacuum pipes, and enabling each vacuum pipe to be connected with the corresponding positionable water permeable pipe; (5) laying another sand cushion and a sealing film; (6) enabling a vacuumizing device to be connected with the vacuum pipes; (7) turning on the vacuumizing device to pump out gas and water under the sealing film, and continuing vacuumizing until the vacuumizing device is unloaded; and (8) after the project is completed, recovering the positionable water permeable pipes. The method disclosed by the invention can be flexibly applied in a complex stratum situation, and the flow cross-section of a draining well is enlarged, so that the problems of clogging of plastic draining plates and 'mud columns' formed in the periphery of the plastic draining plates can be solved; and the water permeable pipes can be recovered and utilized, so that the engineering cost is reduced, and the treating effect of the foundation is greatly improved.