Superconducting fault current limiter(SFCL) can offer rapid and effective current limitation, which is used to improve the reliability and security of electric power network. Experimental modal analysis is performed on a prototype of saturated core superconducting fault current limiter to study the natural characteristics of iron core/winding, and tank of the SFCL. A special vibration measurement system is constructed to investigate the characteristics of SFCL, in which fiber optic sensors are used to directly measure the core and winding vibration. The results show that the vibration spectrum of SFCL during normal operation consists of many high order harmonics with typical vibration characteristics of transformers under DC bias. It indicates that it’s of great necessity to conduct experimental modal analysis on SFCL’s key components during the stage of structure dynamic design to keep them away from resonance caused by high order harmonics, and the vibration of SFCL’s core/winding and oil tank should be monitored on-line during development, test, and operation as both of them have to withstand high intensity vibration with different properties.