Ruddlesden–Popper nickelates have emerged as a crucial platform for exploring the mechanisms of high-temperature superconductivity1–7. However, the Fermi surface topology required for superconductivity remains unknown. Here, beyond the superconducting pure bilayer (2222) phase, we report the thin film growth and ambient-pressure superconductivity of monolayer–bilayer (1212) and bilayer–trilayer (2323) superstructures, together with the absence of superconductivity in monolayer–trilayer (1313) superstructure, under identical compressive epitaxial strain. The onset superconducting transition temperatures range from 46 K to 50 K, exceeding the McMillan limit. Angle-resolved photoemission spectroscopy shows key Fermi surface differences in these atomically engineered structures. In superconducting 1212 and 2222 films, a dispersive hole-like band (γΙΙ) forms an underlying Fermi pocket, surrounding the Brillouin zone corner. By contrast, the top of the flat band (γΙΙΙ) is observed at about 70 meV below EF in the non-superconducting 1313 films. Particularly, the superconducting 2323 films host both γΙΙ and γΙΙΙ bands. The polarization dependence of the γ bands reveals their Ni \({d}_{{z}^{2}}\) origin. Our findings expand the family of ambient-pressure nickelate superconductors and establish a connection between structural configuration, electronic structure and the emergence of superconductivity in nickelates.
