Based on density functional theory, we investigate the ferroelectric and piezoelectric properties of the AlN/ScN superlattice, consists of ScN and AlN buckled monolayers alternating along crystallographic c-direction. We nd that the polar wurtzite (w-ScAlN) structure is mechanically and dynamically stable, and is more stable than the nonpolar hexagonal at conguration. We show that ferroelectric polarization switching can be possible for epitaxially tensile strained superlattice. Due to the elastic constant C 33 softening along with an increase in e 33 , the piezoelectric coecient d 33 of the superlattice is doubled compared to pure w-AlN. The combined enhancement of Born eective charges (Z 33) and the sensitivity of the atomic coordinates to external strain (∂u 3 ∂η 3) is the origin of large piezoelectric constant e 33. Moreover, we show that epitaxial biaxial tensile strain signicantly enhances the piezo-response, so that d 33 becomes seven times larger than that of w-AlN at 4% strain. The tensile strain results in a huge enhancement in e 33 by increasing Z 33 and ∂u 3 ∂η 3 , which boosts the piezoelectric coecient. As short-period superlattice growth and epitaxial strain are already experimentally demonstrated in wurtzite nitrides, our results show a new more controlled approach