Perovskite solar cell (PVSC), after its invention since 2009, has attracted tremendous attention from both academia and industry, because of its low cost, ease of manufacturing features and the sky-rocketing efficiencies being achieved within such a short period of time. Currently, the new efficiency record has reached 21.0%, comparable to that of the commercialized PV technologies developed for decades, such as multi-crystalline Si, CIGS and CdTe thin film solar cells. It is very possible that PVSCs would one day step over the threshold of marketization, share or even overturn the current PV market dominated by crystalline-Si solar cells. However, there are still several obstacles to be overcome on the road towards PVSC industrialization. This paper has reviewed the brief developing history and the current research status of PVSCs, and explained: Why PVSCs are so important in the next-generation solar cells, why organometal halide perovskites work so well as light absorbers, and what the inherent differences are among different cell configurations. The prospects on how to realize scale-up industrialization of PVSCs have also been given in the sequence of efficiency, stability, cost, toxicity, and short-term objectives. Resolutions to the remaining challenges according to their orders of technical difficulty and importance have also been discussed.