The electron transporting layer plays an important role in charge extraction and transporting procedure for mesoscopic perovskite solar cells. Herein, the TiO2-B nanoparticles are used as an electron transporting material in perovskite solar cells for the first time which achieves a high efficiency of 18.83%. Furthermore, the effects of TiO2-B electron transporting layer on the nature of perovskite adsorption layer and the photovoltaic properties of devices are investigated in detail. As a consequence, the high efficiency can be ascribed to perovskite layer with a high crystallinity, resulting in suppressing charge recombination at interfaces, leading to favourable energy level alignment between perovskite and TiO2-B.