The invention relates to a super-soft superfine
polyester fiber and a preparation method thereof. The super-soft superfine
polyester fiber is mainly prepared by the steps of
melt spinning of
polyester through spinneret holes, application of an oiling agent and high-speed winding, wherein the oiling agent at least comprises
fluorine-containing polyether, the
mass of which is more than or equal to 45% of that of the oiling agent, the
fluorine-containing polyether is a random
copolymer of
ethylene oxide, [(1,1,2,2-tetrafluoroethoxy) methyl] oxirane and
propylene oxide, and the
structural formula of the random
copolymer is shown in the specification. The preparation method comprises the steps of metering, extruding, cooling, oiling, stretching,
heat setting and high-speed winding of polyester, thereby obtaining the super-soft superfine polyester
fiber. As the filament
fineness of the super-soft superfine polyester fiber is very high, a fabric has advantages of specially soft and fine hand feeling, soft luster, comfortableness, breathability and good appearance texture and is easy to care, thus being popular with users more and more.