A double-layer nylon zipper, comprising: two zipper tapes, each said zipper tape comprising a narrow elongated fabric strip, two series of teeth (12, 12') respectively located on opposing top and bottom sides of said narrow elongated fabric strip each said series of teeth being formed of a series of coil elements (121, 121') made of a plastic wire material, each said coil element comprising a coil head (122, 122'), said coil head having a width greater than the diameter of said coil elements, a coil body (123, 123') connected to said coil head and a wire groove located on said coil body, characterised by a cloth strip covered over the coil body of each coil element of the series of teeth at the bottom side of said narrow elongated fabric strip, and a stitching line stitched to said narrow elongated fabric strip and said cloth strip and extended over a part of said cloth strip corresponding to the wire groove on the coil body of each coil element of the series of teeth of said narrow elongated fabric strip to secure said two series of teeth and said cloth strip to said narrow elongated fabric strip; and a zipper slider coupled between the interlocking series of teeth of said two zipper tapes, said zipper slider comprising top guard frame wall and an opposing bottom guard frame wall, a division wall vertically connected between said top guard frame wall and said bottom guard frame wall, a nose located on a top side of said top guard frame wall, and a pull tap coupled to said nose, said top guard frame wall and said bottom guard frame wall each comprising a first end (211, 221) and an opposing second end (212, 222), the first end of said top guard frame wall and the first end of said bottom guard frame wall being disposed in a flush manner, said top guard frame wall being relatively longer than said bottom guard frame wall so that the second end of said top guard frame wall protrudes over the second end of said bottom guard frame wall, defining an accommodation space right below the second end of said top guard frame wall outside the second end of said bottom guard frame wall. two zipper tapes, each said zipper tape comprising a narrow elongated fabric strip, two series of teeth (12, 12') respectively located on opposing top and bottom sides of said narrow elongated fabric strip each said series of teeth being formed of a series of coil elements (121, 121') made of a plastic wire material, each said coil element comprising a coil head (122, 122'), said coil head having a width greater than the diameter of said coil elements, a coil body (123, 123') connected to said coil head and a wire groove located on said coil body, characterised by a cloth strip covered over the coil body of each coil element of the series of teeth at the bottom side of said narrow elongated fabric strip, and a stitching line stitched to said narrow elongated fabric strip and said cloth strip and extended over a part of said cloth strip corresponding to the wire groove on the coil body of each coil element of the series of teeth of said narrow elongated fabric strip to secure said two series of teeth and said cloth strip to said narrow elongated fabric strip; and a zipper slider coupled between the interlocking series of teeth of said two zipper tapes, said zipper slider comprising top guard frame wall and an opposing bottom guard frame wall, a division wall vertically connected between said top guard frame wall and said bottom guard frame wall, a nose located on a top side of said top guard frame wall, and a pull tap coupled to said nose, said top guard frame wall and said bottom guard frame wall each comprising a first end (211, 221) and an opposing second end (212, 222), the first end of said top guard frame wall and the first end of said bottom guard frame wall being disposed in a flush manner, said top guard frame wall being relatively longer than said bottom guard frame wall so that the second end of said top guard frame wall protrudes over the second end of said bottom guard frame wall, defining an accommodation space right below the second end of said top guard frame wall outside the second end of said bottom guard frame wall.