In order to improve the performance of the hot wire fiber anemometer, based on the metal film fiber Bragg grating(FBG) hot wire fiber anemometer, the FBG cladding diameter of the anemometer is reduced from 125 μm to 71.6 μm by reducing the thickness of the FBG cladding, the thin cladding FBG hot wire optical fiber anemometer is compared with FBG conventional anemometer. The results show that the initial temperature of FBG hot wire fiber anemometer is increased by 48.3%, the sensitivity of airflow velocity measurement is significantly increased by 61.2%, and limited by the wind tunnel used, the maximum wind speed test range is 20 m/s.