Perovskite solar cells (PSCs) are considered highly efficient and hold great potential for next‐generation photovoltaic devices due to their excellent properties. However, there are some challenges that hinder their mass production, such as toxicity in lead‐based PSCs, nonstability, and high manufacturing costs. This study aims to address these challenges by proposing a device modeling approach to optimize the design of highly efficient lead‐free cesium titanium bromide (Cs2TiBr6) perovskite solar cells. Cs2TiBr6‐based perovskite solar cells have low performance due to the lack of suitable electron and hole transport layers. Therefore, this study utilizes numerical simulations in SCAPS‐1D to investigate the effect of different parameters, including the doping density of optimized hole and electron transport layers, the thickness of the absorber layer, the NA/ND of the absorption layer, and the defect concentration. The study models six different device structures with different hole transport layerss. However, an optimized novel structure device Se/CuSbS2/Cs2TiBr6/IZGO/FTO/Glass has been proposed, with a theoretical power conversion efficiency of 29.19%. This device has a VOC of 1.33 V, JSC of 24.28 mA cm−2, and FF of 90.46%. Overall, this study demonstrates the potential of Cs2TiBr6 as a promising material for perovskite solar cells, providing a nontoxic, green renewable energy solution for the future.