The invention discloses a water-
proof construction method for connected nodes of a foundation slab and a ground wall in a composite surround 
system, and relates to the technical field of underground 
engineering water-
proof construction. The water-
proof construction method aims at the problems that the interface of a new concrete structure and an old concrete structure and the chiseled portion of a bored cast-in-place 
pile are prone to forming underground 
water seepage path, and the construction quality of the foundation slab is influenced. The water-proof construction method comprises that 1, a sunken portion is dug on the edge of a foundation pit, a concrete base layer is constructed, a first 
geosynthetic clay liner is laid to the bored cast-in-place 
pile, and closing up is carried out; 2, the foundation slab to be poured and a reinforcing 
steel bar bracket to be turned downwards are erected and bond, and a space on the edge of the foundation slab to be poured is reserved; the foundation slab is poured, and the bracket is turned downwards; 3, the portions, over the bottom elevation of the foundation slab, of the bored cast-in-place 
pile and a high-pressure jet grouting pile are chiseled away, and a depth D is dug downwards along the bottom elevation of the foundation slab continuously; a base layer is poured on the chiseled portion and coated by a second 
geosynthetic clay liner, and closing up is carried out; and 4, after a pouring belt is poured, the pouring belt and the foundation slab are fixedly connected into a whole.