Fan Blade Out (FBO) is one of the most critical and challenging operational conditions in modern turbofan engine, as the resulting sudden imbalance generates high magnitude transient forces on engine mount, which poses a significant threat to aircraft flight safety. This study focuses on a typical high-bypass turbofan engine, establishing a high-fidelity finite element model based on structural load transfer characteristics. The model accuracy was validated through modal analysis, and the effects of rotor speed, blade out angle, and fracture location on both the engine mount reaction forces and the fan disk center orbit were investigated. The key findings reveal that: (1) Increasing the LP rotor speed induces nonlinear growth in mount reaction forces and substantial fan disk center displacement. A twofold increase in rotational speed from 1450 rpm to 2900 rpm causes the peak reaction force at main mounts increased approximately 150%, rising from 1 × 106 N to 2.5 × 106 N, while auxiliary mounts experience only a 66% increase from 6 × 105 N to 1 × 106 N, indicating a higher impact on the main mounts compared to the auxiliary mounts. (2) Under negative blade out angles, the maximum reaction forces at the main mounts decrease. In other cases, the influence of the blade out angle on the reaction forces and the fan disk center orbit is reduced. (3) The fracture location of the blade has a considerable effect on both the reaction forces at the main mounts and the orbit of the fan disk center.