Abstract: A crosslinkable curing super-branched polyester and the cured product and the preparation method thereof are disclosed. The super-branched polyester has high refractive index and comprises a compound represented by the following structural formula (I). In the formula (I), HBP is the backbone of the super-branched polyester; both a and b are positive integers; the sum of a and b is less than or equal to n; n is more than or equal to 10 and less than 80. In the super-branched polyester, A is represented by formula (II) and N is represented by formula (III), wherein R is methyl or hydrogen atom; the mole ratio of N relative to the total mole of A and N is more than 30 mol %, and the ratio of the total mole of A and N relative to the product of the total mole of HBP backbone and n is more than 0.5 and less than or equal to 1.