The utility model discloses a realize sub -assembly of inside leak protection water of building, include by waterproof of a plurality of nonlocal bottom plate of waterproof material preparation or inland bottom plate, wall surface bottom plate, waterproof of interior corner and outer corner that sealing strip and lower seal strip are installed respectively at the last lower extreme of the protruding interface of adjacent contact in nonlocal bottom plate or inland bottom formation leak protection pool, the mouth of a river is blocked up in the limit formation that nonlocal bottom plate and wall contacted, wall surface bottom plate lays in the wall body of building surface, and waterproof of interior corner is laid in the interior corner and outer corner of building with waterproof of outer corner, a plurality of mutual amalgamation sealing connection of wall surface bottom plate together, wall surface bottom plate and waterproof of interior corner and/or waterproof sealing connection of outer corner, waterproof formation wall leak protection pool of wall surface bottom plate, waterproof of interior corner and/or outer corner. The utility model discloses realize sub -assembly of inside leak protection water of building has that economy, leakproof effect are showing, construction convenience, advantage such as durable.