The interface, referred to as the boundary between two phases, has been demonstrated to play a critical role in catalysis. Fundamental understanding of interfacial phenomena occurring in catalysis will favor the rational design of high-performance catalysts. With the thriving of nanoscience, the nanointerface has also received tremendous attention in nanocatalysis. In this review, we focus on the recent advances in the delicate design and the fine control of various complex nanomaterials with well-defined interfaces based on progress in nano-synthetic methodologies, including metal-metal oxide, metal-metal, metal-non-oxide and metal in confined spaces. Then the challenging issues in the synthetic control of a nanointerface, based on the authors' experiences, are discussed. Finally, the prospects and outlooks for engineering nanointerfaces for nanocatalysis towards renewable energy are presented. We focus on recent advances in the delicate design of well-defined nanointerfaces to promote nanocatalysis towards renewable energy.