The invention provides a liquid-tight zipper capable of sufficiently ensuring the waterproof property no matter where zipper teeth are arranged, and capable of sufficiently ensuring the mounting strength of zipper cloth strips with liquid-tight layers where the zipper teeth are mounted. The invention further provides a method for manufacturing the liquid-tight zipper. The liquid-tight zipper comprises a pair of zipper cloth strips (20), a pair of zipper tooth rows (30) and a zipper puller (40), wherein the zipper tooth rows (30) are respectively arranged on the zipper cloth strips (20) and comprise a plurality of zipper teeth (31); the zipper puller (40) is used for meshing/demeshing the zipper tooth rows (30); the zipper cloth strips (20) comprise a pair of cloth strip components (21), expanded core parts (22) which are respectively arranged on relative cloth strip edges of the cloth strip components (21), and a liquid-tight layer (23) formed on one side of each cloth strip component (21); gaps are formed between the liquid-tight layers (23) and the core parts (22) in the width directions of the zipper cloth strips (20); the zipper teeth (31) are mounted at the core parts (22).