In this article, we have studied the device modeling and optimization of perovskite solar cell with Formamidinium Bismuth Iodide (FA)3Bi2I9 as the absorber layer, PEDOT: PSS (poly (3,4-ethylenedioxythiophene) polystyrene sulfonate) as the hole transport material and C60 (Fullerene) as the electron transport material. Rigorous theoretical investigation has been performed for the device parameter optimization especially the ETL, HTL and active layers. Different aspects of design strategies like temperature, carrier density, series and shunt resistance have been analyzed. The optimized device structure shows maximum ETA of 30.81% with the FF of 83.53% for (FA)3Bi2I9 based perovskite solar cell.