The invention relates to a preparation method of anti-ultraviolet anti-aging polyester slices. The preparation method comprises an esterification reaction working procedure and a polymerization reaction working procedure which are sequentially carried out, wherein in an esterification reaction, a third monomer with larger steric hindrance is introduced; after esterification reaction and before prepolymerization reaction, high-content titanium dioxide serving as a flatting agent, a hindered amine light stabilizer and a hindered phenol antioxidant are added; and after prepolymerization and before final polymerization in the polymerization reaction working procedure, an ultraviolet absorbent is added. The polyester fibers spun from the polyester slices prepared by the method provided by theinvention have excellent anti-ultraviolet and anti-aging performances; and after the polyester fibers are knitted/woven into knitted/woven fabric, test shows that the fabric has the correlated technical index, namely not more than 5.0% of ultraviolet light transmittance, is suitable for outdoor sun perpendicular incidence conditions and has good shielding and anti-aging functions.