Abstract: Permanent magnet biased type HVDC fault current limiter (PMFCL) is one of the most effective faults protecting methods of flexible HVDC transmission systems. However, the traditional PMFCL has a small inductance changing ratio and speed when a fault occurs. Demagnetization of PM inside the PMFCL might occur as well. Therefore, based on the issues mentioned above, this paper proposed a new structure of hybrid magnetic materials based three-limb PMFCL(HMFCL), which has fast responded speed, large inductance changing ratio and low PM demagnetization risk. First of all, according to the essential cause of performance defects in PMFCL, the equivalent circuits were built and analyzed. Combining the characteristic features of nanocrystalline alloy and silicon steel and reconstructing the magnetic topology, the inductance changing ratio and liming performance of the HMFCL would be greatly enhanced without compromising the stability of the PM. After that, parameter analysis and groups of simulations regarding electromagnetic models and HVDC system combination were performed. Finally, the effectiveness of the novel HMFCL topology was verified by prototype experiments. The result shows that the proposed HMFCL can have 3.5 times of inductance changing ratio compared with traditional PMFCL and can significantly restrict the fault current by 50%.