Disclosed herein is a gonadotropin fusion protein or a thyroid stimulating hormone fusion protein, a method for preparing the same and use thereof. ²-subunit of the gonadotropin or thyroid stimulating hormone is fused to an Fc fragment directly or indirectly through a linker, and ±-subunit binds to the²-subunit via an affinity between the ±-subunit and the²-subunit. The fusion protein has a prolonged half-life and less fluctuating activity.