Disclosed herein is a gonadotropin fusion protein or a thyroid stimulating hormone fusion protein, a method for preparing the same and use thereof. β-subunit of the gonadotropin or thyroid stimulating hormone is fused to an Fc fragment directly or indirectly through a linker, and α-subunit binds to the β-subunit via an affinity between the α-subunit and the β-subunit. The fusion protein has a prolonged half-life and less fluctuating activity.