Flow-induced vibration of fuel assemblies will lead to fretting wear and even breakage of fuel rods, increasing the risk of radioactive release and affecting the safe operation of reactors. Key factors affecting the flow-induced vibration characteristics of fuel assemblies operated in pressurized water reactors (PWR) are evaluated, which are based on the equivalent power spectral density (EPSD) method of a turbulent flow and the nonlinear vibration model of fuel assemblies. The study evaluates the sensitivity of the vibration response to coolant density, flow velocity, damping, span length of the fuel rod and pitch. The results of numerical simulations show that the span length, the flow velocity and coolant density are positively correlated with the flow-induced vibration characteristics of fuel assemblies, and the sensitivity of the flow velocity of the coolant is the strongest. The pitch and damping are negatively correlated with the flow-induced vibration characteristics of the fuel assemblies, and the sensitivity of the pitch is more significant. During the design and operation process of reactors, the influencing factors with stronger sensitivity to the flow-induced vibration characteristics of fuel assemblies should be prioritized, such as flow velocity and pitch. Moreover, other positively and negatively correlated factors should be considered for combined utilization, aiming to minimize the risk of flow-induced vibration.