The thermal stability of the PSCs (perovskite solar cells) is one of critical problem for its commercialization. With help of COMSOL software, we create a simplified heat transfer model of PSCs and analyse the temperature distribution and variation of PSCs by means of the numerical simulation. The results show that under the environment temperature of 45ºC and the radiation intensity of 1000 W/m², the temperature at the perovskite layer can reach around 85ºC while the copper substrate used as a heatsink is employed in the PSCs, the temperature at the perovskite layer can be decreased to 75.5 ºC. The performance on the thermal management of the copper substrate with different thickness has also been investigated, from which we can conclude that the thickness of the copper should be optimised.