The invention discloses a device for treating building water leakage through a weak current electro-osmotic drainage method. The device comprises positive pole pipes and negative pole pipes; non-conductive body cushion layers are arranged between the positive pole pipes and the negative pole pipes; water permeable holes are distributed in the positive pole pipes and the negative pole pipes; through holes are distributed in the non-conductive body cushion layers and communicate with the water permeable holes in the positive pole pipes and the negative pole pipes in a guiding mode; and one ends of the negative pole pipes pass through a pipeline and a pump. The invention further discloses a method for treating water leakage. The method comprises the steps that A, an inserting hole is drilled in a building water leakage area; B, the device for treating building water leakage through the weak current electro-osmotic drainage method is inserted into the inserting hole of the water leakage area, and a power supply is started; and C, the pump is started to pump out water gathered in the negative pole pipes. According to the device for treating building water leakage through the weak current electro-osmotic drainage method, water in the deep of a building can be gathered and discharged, and the problem that penetrated water in the leakproof treatment is difficult to treat is solved.