The invention relates to a super-hydrophilicity polyester nanofiber membrane and a preparation method thereof. The preparation method comprises the steps that cyclodextrin, citric acid and sodium hypophosphite are dissolved into a polyester solution, after electrostatic spinning, heating treatment is conducted, and the super-hydrophilicity polyester nanofiber membrane is obtained; the temperatureof heating treatment is larger than or equal to the temperature that cyclodextrin and citric acid start to conduct polymerization reaction. The finally prepared super-hydrophilicity polyester nanofiber membrane is mainly composed of polyester nanofiber and cyclodextrin polymer which is evenly dispersed in the super-hydrophilicity polyester nanofiber membrane, the contact angle of surface water ofthe super-hydrophilicity polyester nanofiber membrane is 0 degree, and required time that water drops are in contact with the super-hydrophilicity polyester nanofiber membrane until the contact angleis changed into 0 degree is shorter than or equal to 1 second. The preparation method is simple in technology, wide in raw material source and low in cost, and has good economic benefit. The preparedsuper-hydrophilicity polyester nanofiber membrane keeps the original structure and appearance of the nanofiber membrane, further has great hydrophilicity, and has great application prospects.