The power conversion efficiency of organic-inorganic hybrid perovskite solar cell has exceeded 24%. The rapid increase in efficiency coupled with its cost-effective fabrication has attracted tremendous attention toward the commercialization of perovskite solar cells. The biggest challenge that hinders the commercialization of perovskite solar cells is the long-term instability of materials and the corresponding devices, which cannot compete with other commercialized solar cells, such as Si cells, in terms of lifetime. The intrinsic instability of perovskite material itself is the most critical challenge faced by researchers. In this study, we discuss the intrinsic instability of organic-inorganic hybrid perovskite materials from the aspects of both chemical instability and phase instability. Suggestions for improving the stability of perovskite solar cell are provided from the perspective of composition design and fabrication process.