It is known that for even integer n ≥ 4, the number of knot and link types with superbridge index n is infinite. But, until now, we only know a few of knot and link types with superbridge index not greater than 3. In particular, it was proved that there are only two link types with superbridge index 2.
In this paper we prove that the number of knot and link types with superbridge index 3 is finite, which was conjectured by G.T.Jin.