Polyester FDY hot melting fiber and preparation method thereof

The invention relates to a polyester FDY hot melting fiber and a preparation method thereof. The polyester FDY hot melting fiber is prepared by taking phthalic acid (terephthalic acid and isophthalicacid), ethylene glycol, diethylene glycol, a glass transition temperature regulator (isophthalic acid sulfonate), a macromolecular modulus regulator (fatty acid ester or long chain diol having a carbon atom number greater than or equal to 5) and zinc oxide as reaction raw materials, and preparing low-melting-point polyester, and then carrying out spinning to obtain the polyester FDY hot melting fiber according to an FDY process. The prepared polyester FDY hot-melting fiber is made of the low-melting-point polyester, wherein the molecular chain of the low-melting-point polyester is composed ofa phthalic acid chain segment, an ethylene glycol chain segment, a diethylene glycol chain segment, a glass transition temperature regulator segment and a macromolecular modulus regulator chain segment. According to the prepar