This series study develops a multifunctional poly(ethylene terephthalate) (PET) fabric with far-infrared function and moisture absorption heating properties for warming clothing. In Part I, the far-infrared function yarn was made by a PET and nano-germanium composite to improve the properties of far-infrared emissivity and far-infrared heating. The moisture absorption heating PET yarn includes hygroscopic heating and antistatic properties. In Part II, this moisture absorption heating PET yarn is made by the hydrophilic PET, and the process parameters optimization for melt spinning is presented. First, in order to improve the hydrophilicity of PET, the modified PET is polymerized by terephthalic acid, ethylene glycol, polyethylene glycol oligomers, and sodium-5-sulfo-bis-(hydroxyethyl)-isophthalate. Then, the hydrophilic PET is made into a moisture absorption heating PET yarn, specified to a 75d/72f fully drawn yarn by melt spinning. The properties of this yarn, including hygroscopic heating, surface resistance, tensile strength, elongation at break and yarn count, are presented. In order to improve the properties of this yarn, the Taguchi method combined with grey relational analysis is used to obtain the optimal multi-quality process parameters for melt spinning. According to experiment results, this modified yarn has excellent hygroscopic heating, surface resistance and elongation at break. At the same time, it is shown that the warming fabric forms from Part I and this modified yarn can achieve far-infrared emission of 89%, far-infrared heating of 6.3 ℃, hygroscopic heating of 1.8 ℃ and surface resistance of 107Ω.