The invention provides a perovskite-based thin film solar cell and a method for preparing the perovskite-based thin film solar cell. The perovskite-based thin film solar cell comprises a transparent substrate, a transparent conducting layer formed on the transparent substrate, a compact layer which is formed on the transparent conducting layer and made of semiconductor materials, a porous insulating layer formed on the compact layer, a porous carbon counter electrode layer formed on the porous insulating layer, and an organic metal semiconductor light absorption material which is filled into pores inside the porous insulating layer and has a perovskite structure. The invention provides application of carbon counter electrodes in the perovskite-based thin film solar cell. Compared with an existing method for preparing the perovskite-based thin film solar cell, the method has the advantages that the counter electrodes are made of carbon materials instead of expensive precious metal materials, and therefore the cost is greatly reduced. The vacuum coating method is replaced by a simple and rapid silk screen print method which allows large-scale production to be achieved, therefore, the cost is further saved, and the achievement of industrial production of the perovskite-based thin film solar cell is facilitated.