The invention provides a super-hydrophobic textile prepared from a modified polyester fiber based on dopamine and a preparation method thereof, the preparation method comprises the steps that a polyester fabric is soaked into different buffer solutions in sequence, nano-particles produced by dopamine polymerization are deposited on the fiber surface adhered with polydopamine, the fiber is finally treated by a low surface energy modifier to obtain the super-hydrophobic textile; the buffer solution at east comprises two kinds of different buffer solutions, namely, a phosphate buffer solution of the dopamine and a trihydroxymethyl aminomethane buffer solution of the dopamine. According to the super-hydrophobic textile prepared from the modified polyester fiber based on the dopamine and the preparation method thereof, the characteristic that the sizes of polydopamine nano particles produced by dopamine polymerization in different buffer solution systems is utilized, autoxidation polymerization of dopamine is utilized to be adhered to and deposited on the fiber surface to form a rough structure required by the super-hydrophobic surface, and the super-hydrophobic surface can be prepared after the rough structure is treated by the low surface energy; the reaction process is simple, the condition is mild; and the water drop contact angle of the super-hydrophobic surface prepared by the invention is more than 150 degree.