The invention discloses a low-melting-point nylon hot-melt yarn for preparing fly-woven shoe uppers, which is formed by polymerizing polyamines and polyacids as reactants, and adding catalysts, modifiers and other auxiliary agents for further reaction; A mixture of decanediamine, pentaethylenehexamine and (1R,2R)‑(‑)‑N‑(p-toluenesulfonyl)‑1,2‑diphenylethylenediamine was chosen for the polyamine; A mixture of sebacic acid, terephthalic acid, and dodecenylsuccinic acid was selected; bis(pentamethylcyclopentadiene) zirconium dichloride, N,N-dimethylanilinium were selected as catalysts A mixture of tetrakis(pentafluorophenyl)borate; the modifiers are 3,5-diamino-1,2,4-triazole, bicyclo(2.2.2)oct-5-ene-2 , a mixture of 3‑dicarboxylic anhydride and 2,2‑bis[4‑(4‑aminophenoxy)phenyl]‑1,1,1,3,3,3‑hexafluoropropane. Nylon thermal fuse not only has a lower melting point, but also has greater fiber strength and elongation, and also has stronger anti-ultraviolet properties and better color fastness, and can be used to prepare fly-knit uppers.