Despite the high power conversion efficiency, the severe performance degradation of organic-inorganic lead halide perovskite solar cells caused by moisture and thermal phase transition is an obstacle to commercialization of the perovskite solar cells. We propose the theoretical lifetime extraction of perovskite solar cells with a mixed-cations lead halide perovskite absorber containing CH3NH3+, CH3(NH2)(2)(+) and Csthorn. The estimated mean time to failure (MTTF) of the triple cation perovskite solar cells is up to 180 days in ambient. Compared with the perovskite solar cells based on CH3NH3PbI3, the triplecation perovskite solar cells, whose power conversion efficiency reaches 18.2% in this study, have a much better performance in terms of thermal stability and humidity stability. Improvements of both performance and stability pave the way for commercialization of perovskite solar cells. (c) 2017 Published by Elsevier Ltd.