The invention discloses a perovskite solar cell and a method of fabrication thereof. The perovskite solar cell sequentially comprises a transparent electrode, a mesoporous P-I-N framework and a counter electrode from the bottom to top; the mesoporous P-I-N framework is composed of an n-type semiconductor layer, an insulating layer, and a p-type semiconductor layer in a sequentially stacked mode, and the n-type semiconductor layer, the insulating layer and the p-type semiconductor layer all comprise mesopores filled with a perovskite material. The preparation method sequentially includes preparing the mesoporous P-I-N framework on a transparent conductive substrate through a spin-coating method or a screen printing method, filling with the perovskite material and preparing the counter electrode layer.