Spiral micro-structured fiber Bragg grating (FBG) coated with nanorod Pt-WO3 hydrogen sensor was fabricated. Femtosecond laser was employed to fabricate spiral micro-structured on fiber cladding of FBG. WO3 nanorods were synthesized by hydrothermal method. Pt (acca)2 precursor was decomposed and Pt-WO3 nanorod particles were synthesized. The molar ratio of the two metals was controlled at Pt∶W=1∶5, the nanorod Pt-WO3 was coated on the surface of micro-structured cladding of FBG. The sensitivity of the double spiral micro-structured FBG sensors is about 2.5 times than that of standard FBG sensors. The response time of the sensor under 1% hydrogen concentration is 15 s to 30 s The sensor has good application prospects in the field of hydrogen sensing.