Iron-based shape memory alloy (Fe-SMA) has overcome the limitations of traditional materials due to its superelasticity and shape memory effects. However, the mechanical performance of bolted connections between Fe-SMA and steel plates (FSBCs) under fire conditions remains unexplored, which significantly limits the practical application of Fe-SMA. To address this research gap, 14 steady-state high-temperature tests were conducted on FSBCs, revealing the failure mechanism of FSBCs under fire exposure. Furthermore, a validated numerical model was developed in ABAQUS, and the effects of geometric parameters of the Fe-SMA plate and bolt on the mechanical behavior of FSBCs under fire conditions were systematically investigated. The results demonstrated that the optimal geometric parameters of the Fe-SMA plate and bolt contribute to superior mechanical performance and economic efficiency of FSBCs. Additionally, the strength reduction method should be appropriately modified to ensure high accuracy in assessing the behavior of FSBCs under fire conditions.