The invention relates to a preparation method for a polyester fiber with compound ultraviolet ray resisting, aging resisting, moisture absorbing and quick drying functions. The method comprises an esterification reaction process, a polymerization reaction process and a spinning process in sequence, and comprises the following specific steps of: in an esterification reaction, introducing a third monomer with relatively large steric hindrance; after the esterification reaction and before a pre-polymerization reaction, adding titanium dioxide serving as a high-content delustering agent, a hindered amine light stabilizer and a hindered phenol antioxidant; after the pre-polymerization of polymerization reaction process and before final polymerization, adding an ultraviolet absorber; and beforethe spinning process, pre-crystallizing and drying polyester slices obtained in the polymerization reaction process, and designing a special-shaped section for the fiber. The polyester fiber obtainedby using the method has superior ultraviolet ray resisting, aging resisting, moisture absorbing and quick drying functions. As provided by testing, relevant technical indexes are that: the ultraviolet transmission is less than or equal to 5.0 percent, the wicking height is more than or equal to 120 millimeters, and the evaporation rate is more than or equal to 0.20g/hr after the polyester fiber is woven into a knitted fabric and a woven fabric.