The challenge of the future hydrogen economy has stimulated studies on developing reliable, sensitive, rapid and long life hydrogen detection method to ensure the safety of the production, storage, delivery and application of hydrogen. Hydrogen is extremely combustible with unusual properties, such as low mini-mum ignition energy (0.017 mJ), high heat of combustion (142 kJ/g hydrogen), and wide flammable range (4–75%) [1]. Compared to the traditional electro chemical hydrogen sensor, the optical fiber hydrogen sensor is greatly applicable to this hazardous or foul environment because of its intrinsic safety, corrosion resistance and antielectromagnetic interference.