ZnO as a typical wide bandgap n-type semiconductor has been broadly employed as an electron transport layer in perovskite solar cells. In this work, we proposed a mesoporous scaffold constructed of vertically aligned ZnO nanorods through a low-temperature water bath. By precisely adjusting the reaction time, well-ordered ZnO nanorods were grown on FTO substrate with different lengths. Taking advantage of the highly visible transmittance, enhanced contact area, shortened electron transport route and compact integrated interface, high-performance mesoporous perovskite solar cells (PSCs) were fabricated. The optimum length of ZnO nanorod based PSC yielded a power conversion efficiency of 14.22% under AM 1.5G illumination. This research suggests that ZnO nanorods with appropriate length are an efficient electron transport layer in mesoporous perovskite solar cells.